Off Campus : Off Campus drive is conducted by a Particular MNC where student appears for drives from different regions and different colleges (No such invitation to any particular college ) anyone can attend this drive if he has the required call letter or reference or whatever is the MNC’s Criteria to attend the drive if anyone fulfill these things he can attend the OFF CAMPUS drive . This drive is organised and conducted by MNC’S people itself .
POOL CAMPUS : In pool campus drive a college will organize the campus drive and he will invite some more colleges to attend the drive , so it’s like a on campus drive but difference is that instead of one college in on campus drive , here multiple colleges students will appear for drive that too who all are invited for the drive .
Hope this will clear your doubts .