FindFirstChild (Function)

FindFirstChild( String Name, Bool recursive )
Returns	Instance found object
Description:	Returns the first child found with a name of Name. Returns nil if no such child exists.

Example

while true do  --Starts up a While loop
  found = game.Workspace:FindFirstChild("Brick")  --This looks in the Workspace for anything named "Brick", and sets the variable "found" to whatever object it finds.

  if found ~= nil then  -- This makes sure that it actually found something. If the variable is nothing, then it ends.

    found.Name = "blah"  --Sets the object's name to "blah"

  end  --End the If loop

end  --End the While loop

Recursive

Recursive sets whether the function should look inside of objects in the calling object, as well as the calling object.

For example, if there is a part in workspace called "Part" and you use:

game:FindFirstChild("Part", true)

It will find the part.