The script editor can be opened via the File > Scripts > Edit scripts... option of the BrainVoyager QX menu or via the script icon.
A script project (*.qsa) is just a container where the scripts are stored.
Although scripts (*.qs) can be saved to disk independently from a script project via the 'Export script' option, when several scripts belong together a script project is a very convenient way to keep the scripts together.
One *.qs script can contain several functions. Variables that are declared outside the functions in a script, are available to all functions within the script.
The function keyword, the () and the {} distinguish the commands within the function from other text, so that the computer knows which part of the text to execute.
The BrainVoyager QX and the QSA language methods are the smallest instruction units.