Data Concepts (20%) - Domain #1

Relational database

A database that stores data in structured tables with rows and columns, using keys to define relationships between tables

Non-relational database

A NoSQL database that stores data in formats other than tables — such as documents, key-value pairs, or graphs

.csv

Comma-separated values; a plain text file format for storing tabular data where each value is separated by a comma

.xlsx

Microsoft Excel spreadsheet file format used for storing structured data with formulas and formatting

.json

JavaScript Object Notation; a lightweight semi-structured file format that stores data in key-value pairs

.txt

A plain text file with no special formatting; stores raw character data

.jpg

JPEG image file; a compressed raster image format commonly used for photographs

.dat

A generic data file used to store raw binary or text data; format depends on the application

Structured data

Data organized in a predefined format of rows and columns — typically stored in relational databases or spreadsheets

Semi-structured data

Data that does not follow a strict table format but has some organizational properties — such as JSON or XML

Unstructured data

Data with no predefined format or structure — such as images, videos, emails, and social media posts

Fact table

The central table in a star schema that stores measurable, quantitative data (metrics/events) about business transactions

Dimensional table

A table in a schema that stores descriptive attributes (dimensions) used to provide context for facts

Slowly changing dimension

A dimensional table attribute that changes gradually over time — such as a customer's address or job title

Bridge table

A table used to resolve many-to-many relationships between fact tables and dimension tables

Schema

The logical structure or blueprint that defines how a database is organized, including tables, columns, and relationships

JSON (JavaScript Object Notation)

A semi-structured, human-readable data format using key-value pairs that supports nested structures

Nested structure

A data structure within JSON where objects or arrays are contained inside other objects or arrays

char

A fixed-length string data type — always uses the defined number of characters (e.g., a 2-char state code like "CA")

varchar

A variable-length string data type — uses only the space needed up to a defined maximum length

nvarchar

A variable-length Unicode string type — supports characters from multiple languages and character sets

Null value

Represents the complete absence of a value — not zero, not empty string — truly unknown or missing data

Spatial data type

A data type used to store geometric or geographic data such as coordinates, shapes, and map locations

Boolean data type

A data type that holds only two values — TRUE or FALSE

Integer

A whole number data type with no decimal places (e.g., 1, 42, -7)

Decimal

An exact numeric data type with a fixed number of decimal places — commonly used for financial data

Float

An approximate numeric data type that stores numbers with decimal points using floating-point representation

Timestamp

A datetime value that records a specific moment in time — often includes date, time, and timezone

BLOB (Binary Large Object)

A data type for storing large binary data — such as images, audio, video, or documents — in a database

CLOB (Character Large Object)

A data type for storing large amounts of text or character data in a database

GUID / UUID

A 128-bit identifier that is globally or universally unique — used to identify records across different systems

API (Application Programming Interface)

A set of rules that allows different software systems to communicate, request, and share data with each other

Data lake

A centralized repository that stores large volumes of raw, unprocessed data in its native format — structured or unstructured

Data lakehouse

A hybrid architecture combining the raw storage scalability of a data lake with the structure and query performance of a warehouse

Data mart

A subset of a data warehouse focused on a specific business unit or department — such as sales or finance

Data silo

Isolated data stored separately from the rest of an organization — inaccessible to other teams or systems

Data warehouse

A centralized repository of structured, historical data optimized for querying, reporting, and business intelligence

AWS (Amazon Web Services)

A leading public cloud provider offering computing, storage, databases, and analytics services

Azure

Microsoft's cloud computing platform providing infrastructure, AI, analytics, and database services

Private cloud

Cloud infrastructure operated solely for one organization — either on-premises or hosted exclusively by a third party

Public cloud

Cloud infrastructure owned by a third-party provider and shared across multiple organizations

Hybrid cloud

A mixed cloud environment that combines private and public cloud resources

Object storage

Stores data as discrete objects with metadata — ideal for unstructured data at scale (e.g., AWS S3)

File storage

Organizes data in a hierarchical folder/file structure — common in NAS (Network-attached Storage) systems

Block storage

Splits data into fixed-size blocks — used for databases and high-performance applications (e.g., SAN)

Local storage

Storage physically connected to or located on a single machine or device

Shared storage

Storage accessible by multiple users or systems simultaneously across a network

Containerization

Packaging an application and all its dependencies into an isolated container for consistent deployment across environments

IDE (Integrated Development Environment)

A software application combining a code editor, debugger, and build tools in one interface

RStudio

An IDE designed specifically for R programming — used for statistical computing and data analysis

VS Code (Visual Studio Code)

A lightweight, versatile IDE by Microsoft that supports Python, R, and many other languages

Tableau

A business intelligence tool used to create interactive dashboards and data visualizations

Power BI

Microsoft's BI tool for building reports and dashboards from multiple data sources

Looker

A Google-owned BI and data exploration platform for creating visualizations and data-driven applications

Anaconda

A Python/R distribution that includes Jupyter Notebook and common data science libraries pre-installed

pandas

A Python library for data manipulation and analysis — provides DataFrame structures for working with tabular data

tidyverse

A collection of R packages (including ggplot2 and dplyr) designed for data science workflows

SAS

A statistical software suite and programming language used for advanced analytics and data management

R

An open-source programming language designed for statistical computing and data visualization

Python

A versatile general-purpose programming language widely used in data analysis, automation, and machine learning

Scala

A programming language often used with Apache Spark for large-scale distributed data processing

SQL Server Management Studio (SSMS)

A Microsoft tool for managing and querying SQL Server databases

MySQL Workbench

A visual GUI tool for designing, managing, and querying MySQL databases

MongoDB Compass

A GUI tool for MongoDB used to explore, query, and visualize NoSQL document data

DBeaver

A free, universal database management tool that supports multiple database types

Toad

A database management tool primarily used for Oracle and SQL databases

Azure Data Studio

A cross-platform database tool by Microsoft for SQL Server, Azure SQL, and other data platforms

Generative AI

AI that can generate new content — such as text, images, or code — based on patterns learned from training data

LLM (Large Language Model)

A type of generative AI model trained on massive text datasets to understand and generate human language

Foundational model

A large-scale AI model trained on broad data that can be fine-tuned and adapted to a wide variety of tasks

Deep learning

A subset of machine learning using multi-layered neural networks to recognize complex patterns in large datasets

NLP (Natural Language Processing)

A branch of AI that enables computers to understand, interpret, and generate human language

RPA (Robotic Process Automation)

Technology that uses software robots to automate repetitive, rule-based business tasks such as automated reporting