Checking Memory

If you mean RAM with memory, you can have a look at Applications > Utilities > Activity Monitor and look at the System Memory tab.




If you mean free hard drive space (HDD - hard drive disk), select your HDD (originally called Macintosh HD), right click in it and select Get Info.




Or you can also use Activity Monitor and look at the Disk Usage tab.

 

^^^ spinnerlys has the answer

 

If you mean RAM, the istatpro widget works really well (and it's free).

EDIT: I guess I was slow to answer, istatpro makes it easier to check your memory, but doesn't provide anymore RAM info than spinnerlys way.

 

Memory = RAM

HDD space = storage capacity


RAM ≠ HDD space