Appreciate has at least three entirely different meanings that I can think of.
1. To be grateful for something.
2. To fully understand something.
3. To increase in value
I’m sure there are more.
I read this as option 2.
1. To be grateful for something.
2. To fully understand something.
3. To increase in value
I’m sure there are more.
I read this as option 2.
For me there's a huge gap between 1 and 2 so it might cause misunderstandings when used in a sentence. I despise a lot of things I fully understand and if I said I "appreciate" them - sounds weird.
Case 1: If it's something useful (e.g. 'your help', 'what you did') then it's more likely about being thankful.
This use of 'appreciate' is also a social action. You say it to make someone feel good for helping.
Case 2: If it's an abstract thing (e.g. 'the importance of', 'the difficulty of') then it's more likely you're talking about understanding.
Usually when you talk about this usage it's because the _fact_ of understanding is important to the speech act. If someone explains the law of gravity you don't say "I appreciate that", you say "I understand that". But if you fell from a height and hurt yourself you can say "I didn't appreciate the law of gravity".
Case 3: If it's intransitive and it's about money ('the car appreciated in value', 'the house appreciated in value').
Finding people that can explain these types of examples to new language learners can be quite difficult, even on language focused platforms/forums.