Given a contract file listed in the contracts folder in the Files hierarchy, there are two different ways to trigger the Compile action.
The first way to compile a contract is by clicking the Compile button, which is the second icon presented in the editor top bar (the puzzle piece icon). Upon activating compilation from the editor, the Output window will open showing compilation progress in text form.
On success, a green message output will read: "Success in compilation". Compilation failure can be caused by a myriad of factors, which often include language syntax errors. In such failure cases and warnings messages, the output will be in a color other than green.
The alternative way of calling the compiler is through the Files hierarchy, on the left side menu. For example, in the Hello World template, click the arrow next to the HelloWorld.sol contract file, in the contracts folder, to expand the available actions. Under the contract item, click the Compile button to start the compilation process.
The compiling step takes advantage of a built-in Solidity compiler, in which the version is pointed out as part of the text output on the screen.