Can someone explain to me the main differences between TBS and RTS games ?In terms of programming what are their major differences and how Total war is able to take advantage of both systems at once ?

The main difference is in the name... One takes place in real time, while the other takes place in turns.

In terms of programming, the difference is that for RTS you will need to be constantly updating/drawing. For TBS, you only need to update when something occurs e.g player hits end turn, so now we calculate the next AI players moves.

Have you played a Total War game? It's pretty obvious how they make use of both systems. The turn-based portion takes place on a large world map, where you move your armies and create castles/cities and the real-time bit is for battles where you fight on a smaller map with 2 or more armies.

Have you played a Total War game? It's pretty obvious how they make use of both systems. The turn-based portion takes place on a large world map, where you move your armies and create castles/cities and the real-time bit is for battles where you fight on a smaller map with 2 or more armies.

+ of course that the battles can be paused at any time, giving them a kind of turn-based feel, even though they are realtime.

That is, it gives you the advantage of turn-based (time to think, give orders, etc), even though it isn't strictly divided into turns. A pretty nice compromise I think.

The battles aren't really RTS though, they are RTT, that is realtime tactics. (no resource management etc)

If we want to analyse a bit more what differs a turn based strategy game from a realtime, we could mention that the former focus 100% on the strategy, while in realtime strategy, fast reactions and actions per minute are at least as important as the actual strategy.