Practical Introduction to PowerShell and Command Line

What Are PowerShell and Command Line? The Difference Between Them

Welcome to Lesson 18! So far, you have been using Windows through its graphical interface—clicking icons, opening menus, and dragging files. Today, you will learn a different way to control your computer: using text commands. This chapter introduces you to two powerful tools: Command Prompt (often called CMD or the command line) and PowerShell. By the end, you will understand what they are, how they differ, and why learning them makes you a more capable Windows user.

What Is the Command Line (Command Prompt)?

The Command Prompt is a text-based interface that has been part of Windows for decades. When you open it, you see a black window with a blinking cursor. Instead of clicking buttons, you type instructions (commands) and press Enter. The computer then performs the task and shows you the result as text.

For example, to see a list of files in a folder, you can type dir and press Enter. The Command Prompt will display the names, sizes, and dates of all files in that folder.

What Is PowerShell?

PowerShell is a more modern and powerful tool. It looks similar to Command Prompt—a blue window with a cursor—but it can do much more. PowerShell uses cmdlets (pronounced "command-lets"), which are specialized commands that follow a verb-noun pattern, like Get-ChildItem (to list files) or Copy-Item (to copy files).

PowerShell can also work with objects (structured data), not just plain text. This means you can easily filter, sort, and manipulate information. For example, you can list only files larger than 1 MB, or copy files that were modified yesterday.

Key Differences at a Glance

• Age and design: Command Prompt is older and simpler. PowerShell is newer and designed for automation and system administration.
• Commands: CMD uses basic commands like dir, cd, and copy. PowerShell uses cmdlets like Get-ChildItem, Set-Location, and Copy-Item.
• Output: CMD outputs plain text. PowerShell outputs objects, which you can filter and process more easily.
• Scripting: Both can run scripts (files with multiple commands), but PowerShell scripts are more powerful and secure.
• Use case: Use CMD for quick, simple tasks. Use PowerShell for complex automation, system management, and working with modern Windows features.

How to Open Each Tool

Let's open both so you can see them side by side.

• Open Command Prompt: Press the Windows key, type cmd, and press Enter. A black window appears.
• Open PowerShell: Press the Windows key, type powershell, and press Enter. A blue window appears.

You can also right-click the Start button and select "Windows Terminal" (modern Windows versions) to access both in one app.

Your First Commands: A Practical Example

Let's try a simple task: listing the files in your Documents folder. Follow these steps in both tools to see the difference.

In Command Prompt:

cd C:\Users\%USERNAME%\Documents
dir

Press Enter after each line. The cd command changes the current folder. The dir command lists files and folders.

In PowerShell:

Set-Location C:\Users\$env:USERNAME\Documents
Get-ChildItem

Press Enter after each line. Set-Location changes the folder, and Get-ChildItem lists the contents. Notice the output in PowerShell includes more details, like file type and size in a structured format.

Common Mistakes Beginners Make

• Typing commands incorrectly: Both tools are case-insensitive for commands, but spelling must be exact. For example, Get-ChildItem works, but get-childitem also works. However, GetChildItem (without the hyphen) will fail.
• Forgetting spaces: Commands and arguments must be separated by spaces. cdDocuments will not work; you need cd Documents.
• Using the wrong tool for the job: If you try to run a PowerShell cmdlet in Command Prompt, you will get an error. Always check which window you are using.

When Should You Use Each Tool?

Here is a simple rule of thumb:

• Use Command Prompt for quick checks, like pinging a website (ping google.com) or checking your IP address (ipconfig).
• Use PowerShell when you need to manage files in bulk, work with system settings, or write a script to automate a repetitive task.

Practice Task

Now it's your turn. Follow these steps to practice what you have learned:

1. Open both Command Prompt and PowerShell.
2. In Command Prompt, type cd Desktop and press Enter. Then type dir and press Enter. Look at the list of files on your desktop.
3. In PowerShell, type Set-Location Desktop and press Enter. Then type Get-ChildItem and press Enter. Compare the output with what you saw in Command Prompt.
4. In PowerShell, try the alias ls instead of Get-ChildItem. Does it work?

This simple exercise shows you the basic workflow of both tools. In the next lessons, you will learn more commands and how to use them to speed up your daily tasks.