Plesk uses the IIS web server
to deliver the pages of your website to clients (such as browsers through which
visitors access your website). The behavior of IIS is defined by variety
of settings.
Default web server settings are specified by the server administrator
(hosting provider). For example, these settings can determine how IIS
process different types of files, how it uses SSL/TLS, and so on.
However, you (as a website owner) can set up custom web server settings
for your website. For example, add a type of the index file, restrict
access to the site, and so on.
Note: You can adjust web server settings for your websites only if your
hosting subscription provides the corresponding permission.