What is the use of default.aspx page(present in deploy location) which comes with Sitecore installation?
If we remove, will it have any impact?
Sitecore: 8.2 update 3
Default.aspx in the standard install of all versions of Sitecore is nothing more than a placeholder page, it serves no purpose in the normal operation of a functioning Sitecore instance. The page itself contains no logic or is not tied to any backend code, and simple outputs the text "Default page".
The page could be useful to check if your IIS instance has been set up correctly, or that a 200 status code is being returned (although the
Heartbeat.aspx is better for this purpose).
You can delete this page if you wish, but unless someone browses to
/default.aspx directly then this page should not normally be served by the system.