Means "and". Use this if you want all the conditions of your macro to be true.
Means "else". Use this if you know some of the conditions in your macro aren't going to be true.
These enclose your conditions. These usually come before your parameters. Sometimes these can be empty to make sure there is always a true condition.
At Symbol (@):
Means "at". Use this to set your target. This also means "target="
Exclaimation Mark (!):
Toggles abilities such as autoattacking, shooting, stealth, etc.