Why does lock table overflow occurs?

why does lock table overflow?
There are many reasons why lock table overflows.
when you try to lock a object or change a object you will see a system message
"lock table overflow", there are amny reasons this will occur.
for example

• small size of lock table
• a particular program sets a large no of locks
• an update process hangs hence setting a large number of locks

above reasons are only a few of the reasons why the lock overflow occurs.