Do datafiles on my Disk Drive grow on thier own?

Disk Drive ---> Datafile ----> Tables

We are using Oracle 7.3, and a couple of our datafiles are almost full,

1. Will My datafiles grow on thier own? ( I say no, but I'm not sure)
2. When my datafile does get full, what happens when someone adds data to a Table that is in that DataFile? Would they get an error? How will Oracle Respond?

Please Help me by sending me E-mail at SatarNag_at_aol.com I thank you in advance for any help.
Satar Naghshineh Received on Fri Jul 25 1997 - 00:00:00 CDT