If you say: "Thanks!" and "Thank you, I appreciate it!" both mean about the same thing, but the second one is a little bit more full of (positive) feeling; it's more effusive. You can't just say "Appreciate" in the place of "Thanks"

according to Cambridge dictioinary: appreciate - to recognize how good someone or something is and to value him, her, or it: There's no point buying him expensive wines - he doesn't appreciate them. or to understand a situation and realize that it is important: We appreciate the need for immediate action. Thanks - words or actions that show you are grateful or pleased about something: They expressed their thanks to the organizers. He wrote a letter of thanks to the hospital. Let us give thanks to God. I can suggest that they are quiet similar but used for different situations/context there is also already asked same question, so here is reference: https://www.italki.com/question/144308

Thanks is every day language to say thank you. Appreciate can mean two things: see examples below: I really appreciate your help. ( I am thankful for your help) I fully appreciate the situation (I fully understand the situation) She felt unappreciated (she felt undervalued) Hope that helps:)