unit testing vs acceptance testing code example

Example: user acceptance testing vs system testing

-System Testing: System testing is finding
defects when the system undergoes 
testing as a whole, it is also known as end
to end testing. In such type of testing,
the application undergoes from beginning till the end.
-UAT: User Acceptance Testing (UAT) involves
running a product through a series
of specific tests which determines
whether the product will meet the needs of its users.