Command substitution

Command substitution is when a computer program takes the result of a command and uses it as an input for another command.

Imagine you have a toy box full of different toys. You want to pick up a toy at random and put it in your backpack. To do this, you could use command substitution. You would first use a command to pick a toy at random, and then use another command to put that toy in your backpack.

In computer terms, this means you could use a command like "ls" to list the files in a folder. If you wanted to take the newest file and move it to a different folder, you could use command substitution to get the name of the newest file (like picking the toy), and then use a command like "mv" to move it to the new folder (putting the toy in your backpack).

Command substitution is a useful tool in programming because it allows you to chain together commands to automate tasks and make them more efficient.