Max I-Node Capacity in Unix

Can any one explain the complete I-Node table and Maximum capacity of file entry on an single I-Node on Unix Kernal. Cause I came to know that even though its 10GB HDD unix can store upto 16GB capacity file on a single I-Node entry. Is there any person(Adv. Linuxer) who can explain the thing in detail. I would be very greatful to him.