# Choose component

You may choose what componets are you going to install on this screen and what installation type will be done.

Possible chooses are:

- Qmaster host – Main component in Grid Engine software. If you want to install Grid Engine you must install exactly one qmaster component per Grid Engine installation.

- Execution host(s) – Hosts that execute the tasks (jobs).

- Shadow host(s) – Shadow hosts provide a high availability feature to the cluster. In case that the qmaster fails (crash, network issue), one of the shadow hosts will take over the qmaster responsibility.

Installation types are as follows:

- Express installation – Targeted for the first time users of Grid Engine. Has significantly reduced set of configuration screens and simplified host selection panel.

- Custom installation – Prompts for all configuration parameters and includes more advanced host selection.