Some students find the difference between operating system software and utility software hard to understand. This video should help clarify the differences (and also the difference between application software and utility software), with plenty of good examples. It also covers the basics of computer software models.

A detailed overview of operating systems, starting with the general tasks they perform (process management, memory management, user interface) and then going into more detail about how these tasks are performed. The video is aimed at GCSE courses and so does not go into lots of detail about how (for example) an OS schedules tasks - but it is more than enough to cover the GCSE syllabus.

The relationships between translators, compilers, and interpreters confuses many students. Throw in assemblers and it can be hard to understand anything about this topic. This video tries to address that confusion, with clear explanations and lots of clear examples.

I'd recommend watching the video Machine, Assembly & High-Level Programming Languages (from the same creator) first, particularly if you're unclear about the difference between assembly language and higher level languages like Python.