Never heard of a Raspberry Pi until I came back to this site last month after a 10 year hiatus. Still don't know what they are but I see it on the home page everyday.
Raspberry PI is an inexpensive linux like miniature PC that has I/O and other remote I/O capabilities so that it can be used for real-time control if wanted...
I use a Raspberry Pi 4B w/ 4GB of Ram to run 4 fish tanks... ph,temp control, orp, do monitoring, level control... all via a graphical interface (node-red).
I've attached digital i/o boards, relay boards, and water quality sensors/probes via the i2c bus (think of something like a RS485 or MODBUS or HART or Profibus, but very short distance...)
Check the NodeRED.org forums under my user name... I have a build thread on it..