Doubts in BODS

Hi Experts,

I am new to BODS. I have some few doubts. Suggest me.

1) Different between Validate Current and Validate All option in BODS.

2) Difference between loading data with Query Transformation and without Query Transformation

3) Difference between types of repositories.

4) Difference between Batch job and Real time job

Thanks

Sravani.N