I am trying to understand the difference between Exploratory and Confirmatory Factory Analysis. I have usually only done CFAs because I would test existing models. Though I know EFA usually precedes CFA, could you please tell me the difference between the two?
EFA is for exploring your data. You don't know how many factors you might have, and you don't know what items might load on what factor.
CFA is when you have a much stronger hypothesis about the structure of your data. You can hypothesize the number of factors, and the items that will load on each factor, and you determine if that model is correct.
An EFA model cannot be wrong. It's a description of your data.
A CFA model can be wrong. It's a test of a hypothesis.