Programming

A computer system is a combination of all the components required to process and store data using a computer.Hardware is the collection of physical devices that comprise a computer system.Software consists of the programs that tell the computer what to do.Programs are sets of instructions for a computer.Programming is the act of developing and writing programs.Application software comprises all the programs you apply to a task.An app is a piece of application software; the term is frequently used for applications on mobile devices.System software comprises the programs that you use to manage your computer.Input describes the entry of data items into computer memory using hardware devices such as keyboards and mice.Data items include all the text, numbers, and other information processed by a computer.Processing data items may involve organizing them, checking them for accuracy, or performing mathematical operations on them.The central processing unit, or CPU, is the computer hardware component that processes data.Output describes the operation of retrieving information from memory and sending it to a device, such as a monitor or printer, so people can view, interpret, and work with the results.Information is processed data.Storage devices are types of hardware equipment, such as disks, that hold information for later retrieval.The cloud refers to remote computers accessed through the Internet.Programming languages such as Visual Basic, C#, C++, or Java are used to write programs.Program code is the set of instructions a programmer writes in a programming language.

Coding the program is the act of writing programming language instructions.The syntax of a language is its grammar rules.Syntax errors are errors in language or grammar.Computer memory is the temporary, internal storage within a computer.Random access memory ( RAM) is temporary, internal computer storage.Volatile describes storage whose contents are lost when power is lost.Nonvolatile describes storage whose contents are retained when power is lost.Machine language is a computer’s on/off circuitry language.Source code is the set of statements a programmer writes in a programming language.Object code is the set of machine language statements that have been translated from source code.A compiler or interpreter translates a high-level language into machine language and indicates if you have used a programming language incorrectly.Binary language is represented using a series of 0s and 1s.To run or execute a program is to carry out its instructions.Scripting languages such as Python, Lua, Perl, and PHP are used to write programs that are typed directly from a keyboard; they are stored as text rather than as binary executable files.The logic of a computer program is the complete sequence of instructions that lead to a problem’s solutionLogical errors occur when incorrect instructions are performed, or when instructions are performed in the wrong order.A variable is a named memory location that can hold different values at different points in time.The program development cycle consists of the steps that occur during a program’s lifetime.Users (or end users) are people who employ and benefit from computer programs.Documentation consists of all the supporting paperwork for a program.An algorithm is the sequence of steps necessary to solve any problem.Desk-checking is the process of walking through a program solution on paper.A high-level programming language supports English-like syntax.A low-level machine language is made up of 1s and 0s and does not use easily interpreted variable names.Debugging is the process of finding and correcting program errors.

Conversion is the entire set of actions an organization must take to switch over to using a new program or set of programs.Maintenance consists of all the improvements and corrections made to a program after it is in production.Pseudocode is an English-like representation of the logical steps it takes to solve a problem.A flowchart is a pictorial representation of the logical steps it takes to solve a problem.An input symbol indicates an input operation and is represented by a parallelogram in flowcharts.A processing symbol indicates a processing operation and is represented by a rectangle in flowcharts.An output symbol indicates an output operation and is represented by a parallelogram in flowcharts.An input/output symbol, or I/O symbol, is represented by a parallelogram in flowcharts.Flowlines, or arrows, connect the steps in a flowchart.A terminal symbol indicates the beginning or end of a flowchart segment and is represented by a lozenge.A loop is a repetition of a series of steps.An infinite loop occurs when repeating logic cannot end.A decision symbol is shaped like a diamond and used to represent decisions in flowcharts.A dummy value is a preselected value that stops the execution of a program.A sentinel value is a preselected value that stops the execution of a program.The term eof means end of file.A text editor is a program that you use to create simple text files; it is similar to a word processor, but without as many features.An integrated development environment (IDE) is a software package that provides an editor, compiler, and other programming tools.A command line is a location on your computer screen at which you type text entries to communicate with the computer’s operating system.A graphical user interface, or GUI (pronounced gooey), allows users to interact with a program in a graphical environment.Procedural programming is a programming model that focuses on procedures or actions as opposed to object-oriented programming.Object-oriented programming is a programming model that focuses on objects, or “things,” and describes their features (also called attributes) and behaviors, as opposed to procedural programming.