Predefined variables list

Server variables

_G -- Table, contains all global variables.
_VERSION -- Version LUA in server.
coroutine -- Table, contains functions for thread.
debug -- Table, contains debug functions.
exports -- Table, contains all export functions server.
math -- Table, contains mathematical functions.
resource -- Element, current resource.
resourceRoot -- Element, root element current resource.
root -- Element, root element server.
string -- Table, contains string functions.
table -- Table, contains functions for tables.

Client variables

guiRoot -- Element, root element all GUI elements.
localPlayer -- Element, local player.
_G -- Table, contains all global variables.
_VERSION -- Version LUA in client.
coroutine -- Table, contains functions for thread.
debug -- Table, contains debug functions.
exports -- Table, contains all export functions client.
math -- Table, contains mathematical functions.
resource -- Element, current resource.
resourceRoot -- Element, root element current resource.
root -- Element, root element client.
string -- Table, contains string functions.
table -- Table, contains functions for tables.

List hidden local variables, that can be in functions-handlers: Server / Client

source -- Element, who call event.
this -- Element, which was attached function-handler.
sourceResource -- Resource, which was called event.
sourceResourceRoot -- Element, root element resource, which was called event.
client -- Client, which was called event. If event called not client - not used.
eventName -- Name event, which called function-handler.

List create user Fro, More details on the functios-handlers.

Element_tree

If list is broken or change - write down update list and this post will be updated.

Original post by MX_Master link