It's been a complex case, and Judge William Alsup, who is overseeing the trial, gave the jury 18 pages of instructions to help them make their decision. The form for their verdict has four questions, some divided into multiple parts. (A copy of the instructions and verdict form is here.)
Judge Alsup himself must also make some decisions based on his interpretation of copyright law, including whether Oracle's APIs can be covered by copyright at all. If he decides they cannot be, the jury's verdict may still be relevant if Oracle appeals Alsup's decision to a higher court.
The jury has been required to attend court in this trial from 8 a.m. to 1 p.m., so that's the time they'll now spend each day debating their verdict until they reach a decision.