noob question - when do I need llamaIndex and when would I need langchain. I learned about llama index first but just found langchain... seems like it does most of the stuff llamaindex does?
langchain is a general app framework, we're focused on the data side specifically. so beyond integrating with vector db's we allow you to define indices over your data (from simple ones to more complex graphs), optimize token usage, ingest from a lot of diff data sources, etc.
