Shell scripting involves writing a series of instructions in the syntax of a particular language to perform tasks on a computer. There are three main types of coding languages: shell scripting languages, general-purpose scripting languages, and programming languages. Shell scripting languages use commands specific to an operating system, while general-purpose scripting languages use statements and modules independent of the operating system. Programming languages are used to compile executable files that can be installed on an OS and run as an app.

Shell scripting is often referred to as a glue language because it's used to automate and orchestrate functions across multiple OS and app software. Scripts can be developed in basic text editors, but using editors with script support or integrated development environments (IDEs) enhances productivity by providing syntax parsing, highlighting, autocomplete features, and debugging tools.

In Linux, shell scripts have a .sh extension and start with a shebang line that designates which interpreter to use, such as Bash or Ksh. Each statement in a script is typically added on separate lines. Shell scripts must have execute permission set to run, and they can be executed from the working directory or with a full path.

Basic script constructs include comments, variables, branches, and loops. Comments assist with maintaining code and are indicated by a special delimiter, typically a hash sign (#). Variables are labels for values that can change during script execution, while branches and loops allow for conditional execution and repeated statement blocks, respectively.

Windows supports several shell coding environments, including PowerShell, Visual Basic Script, and the CMD interpreter. PowerShell combines a script language with prebuilt modules called cmdlets for Windows and Active Directory management. Visual Basic Script is based on Visual Basic and is identified by the .vbs extension. Batch files use the .bat extension and are written for the basic Windows CMD interpreter.

JavaScript and Python are platform-independent scripting and programming languages. JavaScript is used for interactive web-based content and web apps, while Python is a general-purpose language for automation scripts and software apps. JavaScript files have a .js extension, and Python files have a .py extension.

Scripting is commonly used for automation, such as restarting machines, remapping network drives, installing applications, initiating updates, performing backups, and gathering information/data. Best practices for scripting include mitigating malware risks, preventing inadvertent system-setting changes, and avoiding browser or system crashes due to mishandling of resources.