is a technology that, should one wish to host ASP.NET websites then YES
, the hosting machine has to have it installed.
and you have to make sure you install ASP.NET AFTER
IIS or you will have to register the ASP.NET to the IIS later manually.
is the tool with which you host websites, all kinds of websites, ASP.NET sites are merely one example). IIS - Internet Information Services
(formerly called Internet Information Server)
To simply consume a website - NO
, you don't have to install ASP.NET, you just need a browser.