Plesk Components

Plesk manages the work of web, mail, DNS, and other services.
Technically, Plesk does not provide the services by itself; it just
takes control over a number of third-party components. For example, when
a customer creates a website through the Plesk GUI, Plesk propagates
this request to a web server (Apache or IIS) and the latter adds a new
virtual host to the system. The list of components is defined during
Plesk installation (see the Deployment
Guide for details).
Plesk allows you to view the list of installed components, add new ones,
switch between interchangeable components, and remove them (only in
Windows).

Viewing Plesk Components

You can view the list of installed components and their versions in
Tools & Settings > Server Components. Plesk for Windows has an
additional indication of a component state (the appearance of the icons
depends on the Plesk theme):

• means that Plesk is using this component, and the
  component is working.
• means that Plesk is not using this component
  (usually because a license key has expired or missing), but the
  component is working.
• means that Plesk is not using this component
  because the component is stopped.
• means that Plesk is not using this component, but
  the component is installed on the system and is available.

Installing Plesk Components

If you did not include a component in your Plesk installation, you can
add it later in Tools & Settings > Updates > Add/Remove Components.

Switching Between Interchangeable Components

Some Plesk components are interchangeable. For example, in Windows you
can use either MS DNS Server or BIND as your DNS server; in Linux you
can choose between Postfix and Qmail for mail delivery, and so on.

On Plesk for Linux, you can switch between interchangeable components
in two ways:

• Using service settings. Some Plesk components with a similar
  purpose can be installed side-by-side on the same Plesk server. For
  example, if you have two installed antivirus components, you can
  specify the one that will process your mail in Tools & Settings >
  Mail Server Settings.
• Using Plesk Installer. Some Plesk components with a similar purpose
  do not allow side-by-side installation. For example, there can be
  only one mail server in Plesk: either Postfix or Qmail. In this case,
  you should choose the component you want in Tools & Settings >
  Updates > Add/Remove Components.

On Plesk for Windows, you can switch between interchangeable
components in Tools & Settings > Server Components. To perform the
switch, click on the component name (for example, Mail Server) and
select the required component from the list.

Removing Plesk Components (Windows)

If you no longer need a certain Plesk component, you can remove it from
Plesk in Tools & Settings > Updates > Add/Remove Components
or by clicking the Add or Remove Components link on the
Home page.