One Concept, Many Definitions¶
It's really common for a concept (especially in Maths) to have many non-conflicting definitions[^1]. For example, a formulae and an implementation in a programming language are different but can produce the same result.
If you don't recognise the concept, you should still try and generate examples to try and create the connections to your pre-existing understanding.
[^1] from a Programmers Intro to Maths