GIS ALL SECTIONS

What is the key difference between a Table Join and a Spatial Join? 

A Table Join links by a common attribute field; a Spatial Join links by geographic location.

What does Compare Feature Classes do?

A geoprocessing tool that compares two feature classes and reports differences in geometry, attributes, and spatial reference.

 What is the Buffer tool used for? 

Creating zones at a specified distance around input features. Used for proximity analysis: finding areas within a certain distance of features.

What is the Clip tool used for?

Cutting out a portion of one layer using a polygon from another layer.

What is the Dissolve tool used for?

Merging adjacent or overlapping features based on a common attribute value. 

What is the difference between Intersect and Union? 

Intersect outputs overlapping areas; Union outputs all areas from input layers.

What is Batch Processing in ArcGIS Pro?

running a geoprocessing tool on multiple datasets at once. 

What is ModelBuilder? 

A drag-and-drop tool for chaining multiple geoprocessing tools into a repeatable workflow.

What is an Iterator in ModelBuilder?

A tool that loops through data, repeating a process for each item. Only one iterator can be used per model.

What is the difference between a Raster Tool and a Raster Function?

A Raster Tool creates a new permanent raster file; a Raster Function processes on the fly and doesn't create a file unless exported.

What does the NDVI (Normalized Difference Vegetation Index) raster function measure?

Plant cover and greenness over an area. (NIR - Red) / (NIR + Red). Values from -1 to 1. Negative = water, 0 = barren or urban, positive = vegetation.

What does the Shaded Relief (Hillshade) raster function do?

Creates a 3D-like visualization of a surface raster to show topography.

What does the Reclassify raster function do?

Groups continuous raster values into discrete classes.

What is the correct way to share a workflow that chains multiple raster functions (extract bands, NDVI, colormap) on the fly?

As a raster processing template (XML file).

What is the Raster Calculator used for?

To write math expressions with raster layers. e.g. Elevation * 2, NDVI > 0.3.

To find the shortest route between two points, which toolbox should you start with?

Network Analyst Tools: specifically designed for routing and transportation network problems. Other toolboxes focus on other analysis, like overlays or statistics.

Which of the following is considered a geoprocessing environment setting: Output Coordinate System, Output Format, Processing Extent, or Extent?

Output Format is NOT an environment setting; it's a tool-specific parameter.

What is the main advantage of using a Raster Function instead of a Geoprocessing Tool?

a raster function gives a quick preview, applies only to the pixels visible on screen and doesn't create a new file unless exported.

Which type of Spatial Analysis tool would you use to find clusters of high and low values in your data?

Spatial Statistics (Hot Spot Analysis / Cluster Analysis)

What is a Geographic Coordinate System (GCS)?

A coordinate system that uses a 3D model to define locations on the earth's surface using lat and long.

What are the four components that define a Geographic Coordinate System (GCS)?

Angular units of measure, Prime meridian, Spheroid, and Datum. (The angular units are typically degrees; the prime meridian sets the zero point for longitude; the spheroid models the earth's shape mathematically; and the datum defines the origin and orientation of the graticule)

What is a Datum in the context of a Geographic Coordinate System?

The datum decides how the spheroid is anchored to the earth/geoide, so orientation and origin of graticule. different datums, NAD or WGS, shift coordinates by several meters for the same location.

 Why are there multiple spheroids (mathematical models of the earth) used for different Geographic Coordinate Systems?

The earth's surface is not symmetrical; the semi major and semi minor axes that fit one region don’t necessarily fit another.

What is a Projected Coordinate System?

A coordinate system that defines locations on a 2D map surface. A PCS takes a 3D GCS and "flattens" it via a map projection.

What are the three main types of map projections?

Cylindrical, Conic, and Azimuthal (Planar). Cylindrical projections project the earth onto a cylinder (good for equatorial regions); conic projections project onto a cone (good for mid-latitudes); and azimuthal projections project onto a flat plane (good for polar regions)

What is a Conformal projection?

A projection that preserves local shape and angles but distorts area. e.g. Mercator

What is an Equal Area projection?

A projection that preserves area (size) but distorts shape. Used when comparative size of region matters (e.g. Albers Equal Area for thematic maps showing population density).

What are the four types of distortion that map projections introduce?

Shape, Area, Distance, and Direction. impossible to preserve all four. A projection preserves one or two tops.

True or False: All map projections cause distortion in at least two of the following spatial properties: area, direction, distance, or shape.

True.. You have to choose which property to preserve based on map purpose

What is the Geoid?

The true measurable shape of earth's surface: mountains, ocean trenches, uneven gravity. Spheroids are smooth approximations for mapping and calculations.

What is the key difference between Angular Units and Linear Units?

Angular units (decimal degrees or degrees/minutes/seconds) measure positions on a sphere; Linear units (feet, meters) measure straight-line distances on a flat surface. 

GCSs use Angular Units. PCSs use Linear Units.

Which datum is used by default for most GPS devices and global web maps?

WGS84. It is a global datum, meaning it works everywhere but is not perfectly accurate for any single region.

What are the three primary geometric shapes used to represent vector data in ArcGIS Pro?

Points, Lines (Polylines), and Polygons. Points are X,Y coordinates; Lines are connected vertices; Polygons are closed boundaries.

A user needs to model a continuous surface, like elevation or temperature, across a landscape. Which data model is most appropriate?

Raster. Rasters use a grid of equally sized cells, each cell holds a value. Vectors are for discrete, bounded objects, while rasters are for continuously changing phenomena.

An analyst needs precise property boundaries and exact owner information for individual parcels. Which data model is best suited for this task?

Vector, specifically Polygon. Raster struggles to define precise boundaries with a grid of cells and values. vector is for discrete bounded objects

What is the hierarchy of data storage inside a File Geodatabase (.gdb)?

Geodatabase container (city.gbd) → optional Feature Datasets (transportation) → Feature Classes / Tables (roads, intersections, buildings) → Rows/features

What is the only valid reason to store a Feature Class inside a Feature Dataset rather than as a standalone item?

To build a Topology, Network Dataset, or Terrain. (Feature Datasets are not for organization. If your data doesn't need topology rules, network routing, or 3D terrain, keep it as standalone Feature Classes )

 What is a Coded Value Domain in a geodatabase?

A rule that restricts attribute entries to a predefined dropdown list of values.

What is a Range Domain in a geodatabase?

A rule that restricts the range of possible values to a numerical minimum and maximum.

What is the purpose of a Subtype in a geodatabase?

To categorize within a Feature Class, keeping data organized and in one map layer. (e.g., a Subtype lets "Transmission Mains" > 36 inches, while "Service Lines" < 6 inches, all in the same WaterMains feature class.)

What is a Relationship Class in a geodatabase?

A permanent, database-enforced link between two tables or feature classes based on a matching field which saves storage. (Unlike a temporary Join, a Relationship Class establishes cardinality and can enforce rules like Cascade Delete.)

What are the three types of cardinality (relationships) used in a Relationship Class?

1:1, 1:M, N:M. 1 to 1 is one record to one record, 1 to many is one owner can have many parcels, many to many is many parcels have many owners

 What is an Attachment in a geodatabase?

External files (like PDFs, JPGs, or Word docs) attached directly to individual feature records.

What is "Cascade Delete" in a Relationship Class?

determines what happens to related records when the primary record is deleted. ON means deleting primary record deletes related records. OFF means GIS blocks deletion and throws an error.

What is Topology in a geodatabase?

A set of rules that define how features can share geometry.

What are examples of a Topology rule?

"Must Not Overlap”, “Must Not Have Gaps”,  "Must Be Covered By". These maintain spatial integrity.

Where must Topology be stored in a geodatabase?

Inside a Feature Dataset. cannot be applied to standalone feature classes.

 What does "Must Not Have Gaps" topology rule enforce?

That polygons be adjacent with no empty space between them. Used for datasets where every area should be completely covered.

 What does "Must Be Covered By" topology rule enforce?

 That features in one layer must be covered by features in another layer. e.g. Roads must be covered by the city boundary.

What is Metadata in GIS?

"Data about the data" - documentation about who created it, when, coordinate system, and restrictions.

 What is the purpose of Snapping in ArcGIS Pro editing?

forces the cursor to connect to existing vertices or edges preventing gaps

What are Sketch Tools used for?

Drawing points, lines, and polygons with options for curves and tracing existing features.

What is Python scripting used for in ArcGIS Pro?

Automating complex workflows that ModelBuilder can't handle.

Can you change the type of a Domain after it is created?

No. You can edit codes and values, but you cannot change between Coded Value Domain and Range Domain.

What is Symbology / layer symbology?

How you visually represent the data in a feature layer.

What’re the main types of symbology?

Single Symbol, Unique Values, Graduated Colors, Graduated Symbols, Unclassed Colors

Single Symbol

Every feature (row) looks identical. use when only location matters. (e.g. all fire hydrant locations)

Unique Values

Each distinct value in an attribute (column) gets its own symbol. Use for categorical attributes.

Graduated Colors

Numeric values grouped into classes, and each class gets a color from a ramp. use for rates or densities.

Graduated Symbols

Numeric values grouped into classes, each class gets a different symbol size. use for size to communicate magnitude.

Unclassed colors/symbols

Numeric values attributed to a color/size ramp without grouping. Smoother than groups, harder to read exact values.

What’re the two labeling engines in ArcGIS Pro?

Standard: basic placement, fast but limited

Maplex: advanced placement, handles curves, fitting, conflict, and abbreviation.

Position (maplex labeling)

Where the label goes relative to the feature e.g. on the boundary or in the center of a polygon, curved with the line feature

Fitting Strategy (maplex labeling)

How to make labels fit e.g. stacking, font size, abbreviation, key numbering

Conflict Resolution (maplex labeling)

Which label wins when they compete for space, this is based on feature weight (0-1000), how important a feature is.

Abbreviation (maplex labeling)

Street to St, Road to Rd, only applies to keywords, endings and translations when full labels won’t fit.

Temporal Data

Data that changes over time

How does a Layer become Time-Aware?

Time is configured on the Time tab of Layer Properties. A Time Slider automatically appeares when at least one layer in the map has temporal properties configured.

How is a layers time defined/configured?

In three ways.

1. single time field: every feature has one time stamp

2. start and end time fields: every feature has a duration

3. Fixed time extent: the whole layer has one time range, this is set manually.

What are ArcGIS Pro’s scene types.

Local and Global. Local is for a smaller extent, global spans the globe such that earth curvature matters. choose between them based on data extent.

Local Scenes

Flat models, projected planes you can tilt and rotate. Planar, not spherical. it supports PCSs and GCSs.

Global Scene

Spherical models, think google earth. Supports WGS and CGCS. (world geodetic system / Chinese geodetic coordinate system)

How 3D objects interact with Scenes

Both scenes support them, they’re not just extruded polygons, but 3D meshes. You need to create a 3D object scene layer or 3D object feature layer.

What is extrusion in a 3D scene?

Extending 2D features vertically based on a numeric attribute or value.

What are Queries in ArcGIS?

Queries select features based on criteria. There are different types of queries: attribute, spatial, and arcade.

Attribute Query

Select features based on values in the attribute table. e.g. select parcels where Zoning = ‘Residential’ AND Area > 5000

Spatial Query

Select features based on their location relative to other features. e.g. all points that fall inside certain boundary.

Arcade Expression

ArcGIS’s expression language for: label expressions, symbology, popups, field calculations.

How to Enable Maplex

Select the layer you want to label, click the labelling tab in the ribbon, in map group click more, select use maplex.

Where do you change the coordinate system for an entire map in ArcGIS Pro?

Map properties → coordinate systems tab. This is specifically visualization section workflow.

What does “ranged data” refer to in visualization?

Numeric data visualized with graduated colors / symbols. Temporal, ranged, and 3D are the three data visualization categories.

Map Frame

element of the layout that displays a map. A layout can have multiple frames.

Dynamic Text

Text linked to a map or system property that updates with it. e.g. credits, date saved, coordinate system used.

Spatial Map Series

A single layout that generates multiple pages, each showing different geographic extent, extent defined by an index layer.

What’s an Index Layer

A feature class that defines boundaries or locations for each page of map series. e.g. counties in a state, states in a country. each county defines the extent of one page

Four Required Fields for a Spatial Map Series

Map frame (which frame changes per page), index layer, name field (page name, e.g. CountyName), sort field (page order, e.g. CountyID)

Index Layer Restriction

The index layer for a map series must be a feature layer, not a raster.

Clip To Graphics Extent

exports only the area of the page containing map or layout elements, not the full blank page.

Export Layout vs. Export Map

Export layout is page-based (pdf, printing), export map is view based (pixels, image file). Layout preserves page composition, map captures current map view

Write World File

an export option that makes a sidecar file with georeferencing info so the exported image can be used as a raster data set. allows image to display in correct location in GIS. not for 3d

What does Export Completed with Warnings mean

The file was created but some content may not be rendered correctly. common causes are unsupported transparency, or symbology not supported in chosen format.

What is Analyze Before Sharing

Before sharing a web map gotta run Analyze. it finds errors (blocks sharing) and warnings (affect performance).

What does Sharing a Web Map create

creates a web map and a web feature layer in your organization’s content. Sharing level controls who can access it.

what’s a Map Package

.mpkx: a file that packages a map and its data for sharing with other AGP users. Unlike a web map, which lives in a portal, a map package is a portable file.

what’s a Project Package

.ppkx: a file that packages the entire project. maps, layouts, data, tool boxes, everything. for sharing with other AGP users.

what’s a Tile Package

.tpkx: pre-rendered map tiles for fast web display, shared or published to AGO. Created with Create Map Tile Package. Tiles are cached images, not live data.

Exporting Data versus Exporting a Map

Exporting a map makes an image or pdf of the view. Exporting data creates a new dataset on disk (shapefile, feature class, csv).