Like most languages, PowerShell supports the use of functions. Functions are reusable bits of code with a name wrapped around them. This lets you make multiple calls to your function name allowing you code reuse.
PowerShell actually has two types of functions, Basic and Advanced. Basic functions are a lot like the 1974 VW SuperBeetle I owned back in college. No frills but useful, gets you where you are going. Did 0 to 60 mph in under 5 minutes. Most of the time.
Advanced functions have a lot more capabilities, and are more akin to a Tesla. Lots of fancy design, can do cool things, and depending on your need might be worth the extra investment.
Robert’s post is all about those basic functions, so check it out.