The compilation can be started via the menu entry in the main menu
Main Menu ⇒ Source ⇒ Compile
or with the keyboard shortcut (key binding)
CTRL + SHIFT + C
From the Remote Explorer the compilation can also be started via the context menu (right-click) of a source member.
The currently open source member in the active editor or the selected source member in the Remote Explorer will be compiled whereas the source member in the active editor takes precedence over the selection in the Remote Explorer.