IsPostBack property in ASP.Net

• Every time a page is requested or posted, the initialization code i.e., the code in Page_Init and Page_Load events is executed.
  
• This process slowdown the loading of your page.
  
• The IsPostBack property of the page allows you to check if the page is required for first time or not.
  
• The IsPostBack = true then the page is run as a result of round trip.
  
• The IsPostBack = false then the page is displayed for first time.

Note: You can indentify that the page is post back by the IsPostBack property. If IsPostBack is True means, the page has been posted back