IIS

Internet Information Services is an extensible web server created by Microsoft for use with the Windows NT family. IIS supports HTTP, HTTP/2, HTTPS, FTP, FTPS, SMTP and NNTP.

-- Wikipedia

General information

ASP.NET Web Project File Types

File Types Managed by ASP.NET

File Types Managed by ASP.NET

.txt
.asax
.ascx
.ashx
.asmx
.aspx
.axd
.browser
.cd
.compile
.config
.cs
.vb
.csproj
.vbproj
.disco
.vsdisco
.dsdgm
.dsprototype
.dll
.licx
.webinfo
.master
.mdb
.ldb
.mdf
.msgx
.svc
.resources
.resx
.sdm
.sdmDocument
.sitemap
.skin
.sln
.soap

File Types Managed by IIS

.asa
.cdx
.cer
.idc
.shtm
.shtml
.stm

Static File Types

.css
.htm
.html