Another noob bites the dust...

[Hexenhammer]

I assume you can extend the capabilities of the interpreter by adding libraries

..and glue code, yes. For example LÖVE uses OpenAL for sound. So in addition to the Lua interpreter LÖVE also links OpenAL. And then there is the glue code which connects the Lua interpreter with OpenAL.. and suddenly there is sound!

Note that you cannot do this from Lua, LÖVE is a C++ application which links against the Lua interpreter and many other libraries and makes everything work as a coherent whole. This is complex business and a noob shouldn't concern himself with that.

(isn't a framework sort of a library ?).

"Framework" is a rather vague term. One common definition which distinguishes libraries from frameworks is that a library is called by your program, while a framework calls your program. In that sense LÖVE is actually a framework. LÖVE first executes your conf.lua file, then your
main.lua file, and then enters a loop calling specific functions of your program (love.update, love.draw..).