It most frequently means “bytes per second” and is a count of how many bytes are streamed every second. However, it confusingly sometimes means “bits per second”, usually on very slow data connections. Nowadays, you can mostly assume it means “bytes” and not “bits” but the thing about flight software is that you should never assume anything, so ask the knowledge keepers of the code to be certain.

Short for “Board Support Package”. Sometimes also known as the “Platform Support Package”. This is the layer of code closest to your hardware. It’s got the drivers, low-level execution code, and other software specific to your unique hardware. When you power on, it’s what the operating system and (if you’re using cFS) the Core Flight Executive layers use to initialize and talk to the hardware.

Because hardware is always changing and different projects use different hardware variations, this is an area you may find yourself focusing on in software development. You can make a whole career out of it. However, if you’re using common hardware (like a Raspberry Pi) then the BSP is already written for you. Vendors may also have software for you already.