Hi there!
Ps in UNIX is a command that helps you see all the running programs and processes on your computer. Think of it like a big list of all the things your computer is currently doing.
When you type "ps" into the command line, you'll see a bunch of information listed out in columns. Each row represents a different running process, and the columns show you details like the process ID (a number that identifies each process), the user who started the process, how much CPU time the process is using, and more.
You can use ps to figure out which programs are using up a lot of resources on your computer, or to check if a specific process is running (maybe you're not sure if a program like Chrome is already running or not).
So basically, ps in UNIX is like having a big cheat sheet that tells you all the different tasks your computer is currently working on. It's pretty handy!