confused.. network solution choices

im new to networking, trying to learn it, before, when i was learning unity i looked at networking and thought whooa way over my head, but now im trying to learn it... anyway,

so... im confused about something...
these networking solutions say stuff like 100 concurrent users free. (smartfox)

uh, so these networking solutions, like photon, or smartfox, they always have to be on the internet??
they Always use Their servers? .. thats the way it sounds...
how does it limit you to 100 ccu if you have your own server?

is it 100ccu on 1 server (could have infinite servers)
or is it 100ccu for Game (10 servers, 10 ccu each)

what if iam LAN, could i do, like 200 concurrent users for free LAN? (well license says not, but, is it actually possible?)

i dont understand... like, smartfox or photon is a code basis, an engine, architecture, whatever to adapt your game to? or its a server program that provides us servers for our players/clients to play the game foremost?

anyway...
what iam concerned with is, i should be able to create my game, and 1000 years later i could still play it LAN or even on the internet (assuming like IP addresses still exist LOL, and still running same windows, etc, but thats not the point) ... the point is, i dont want to rely on a third party to still exist in 10+ years from now..

is the photon / smartfox (and/or others) computer programs independent of internet?

like, with most files, i Download it and, i basically Own it for all time... (not legally, but in actuality)
like, i can still play mario..

always online stuff is really really REAALLY LAME and i have 0 interest in any of it...
(theres some games you can ONLY play it multiplayer if you download pirated copy... legit purchasers cant, because master server doesnt exist anymore = STUPID!)


shouldnt it be like, download architecture, integrate with game, players/clients can run their own servers, server program is shipped with game (or integrated in game), 1000 years from now (theoretically) can still host game server