Deciding on your goal and how to achieve it
If you take a look around you in the gym, everyone is working towards their goal. Therefore the variation in exercises will differ from person to person. What you need to decide on is what your goal is and don't take aspects from everyone else goal.
All to often people in the gym have a mixed range of goals. They binge at the weekend so Monday-Wednesday they're "Dieting". Wednesday - Saturday they're deciding that they're "bulking". So over the course of 6 months they haven't made a change to their body shape at all.
If you're bulking then you should be training (and eating) as though your looking at putting size on. If your Cutting/dieting then you need to be training and eating to represent that also.
Don't become mixed up and train like your friends are doing if your goal is completely different.