For MSI, MSU, and MSP installs there are a number of options which can be passed to msiexec.exe as part of the install.
Operation
Install is the most common option, but the others are available if you wish to use them.
Restart
Some installs must be restarted to complete the installation (such as when files are in use). You can decide how to the restarts will be handled. The (not set) option doesn't include any option for restarting, this will use the install's default option or you can include some other option on the command line (see below.)
Quiet
Most often you will want to leave checked (see Silent Options for more information) but there may be times when you want to use a different command line option than /q or when the install doesn't work properly with this option.