Difference between LCA, LDA and LEA

Hello Experts,

Whenever i execute LC10, i see 3 DB connections - LCA, LDA and LEA.

I do have some basic questions which i couldnt find answers for:

1. How to find out which DB connection is used in the system - LCA, LDA or LEA.

Or all the three will be used for LC to be functional?

2. If only LCA is used, how to uninstall or remove the connections for others?

Thanks,

Subbu