What is View State ?

View State is a technique used by asp.net webpage to persist changes to state of a webform between postbacks.

View state of page is by default stored in hidden form field named _viewstate.

ADVANTAGES:- 

• Automatic retention of page and control state
• server resources not required.(View state can also be stored in server side.)
• The values in view state are compressed and hashed

DISADVANTAGES:-

• view state increases the page size since it is stored in the page itself.
• Although view state stores data in hashed format they can be tampered.