javascript - Server side programming vs Client side programming -

i'm trying understand concept better. whole point of server side programming allow communicate others? whether new ideas or data can't stored locally on client because way information?

there several typical software architectures:

• non-networked application (does not communicate, client-only)
• server-client application (has typically 1 or more central servers, , multiple clients contact server(s))
• peer-to-peer application (only has clients communicate each other).

here, client typically part of application executing on user's computer, user interacting with. server defined part of application user not interacting directly, , not on computer somewhere else. separation can of number of reasons: data size, data security, data availability, or coordination.

for example, when go google on web browser, web browser client. google server. computer not know on web is; google has pretty idea.

for example, if play mmorpgs world of warcraft, game client, , blizzard's computers server; tell server doing, , server tells results, pen-and-paper gamemaster. without server, couldn't know else doing.

or, if want consult atomic clock @ u.s. naval observatory, again, client, clock server; contact because, obviously, don't know correct time, , does.

now, example, might server might not needed in cases. example, in mmorpg case, couldn't players contact each other directly? first problem discoverability: how find each other on internet? there has central location tell everyone else's address. if server did, have contact of online players (and there lot of them) ask them are, , if on same map ask them same question very often; internet connection not able it. there security consider: server makes sure (or should make sure) not teleporting around on map changing game's code , telling other player bogus values. example, if client responsible remembering how gold player has, trivial become rich quickly: lie others.