From Wars Wiki
The Wars Series is a loose series of games made up of various small subseries.
The Famicom Wars is two games involving the battles between the members of Allied Nations. Both games are released on Famicom Disk Systems (Famicom and Super Famicom)/Nintendo Entertainment Systems (NES and SNES). In Japan the Battalion Wars series is considered to be part of the Famicom Wars series.
Game Boy Wars
The Advance Wars series is four games split into 2 smaller stories, one involving the Allied Nations against Black Hole, and the other involving 12th Battalion against Intelligence Defense Systems and its customers Lazurian Army, and New Rubinelle Army.
The Battalion Wars series consists of two games. The first sees Xylvania in pursuit of global conquest, and tricks the Tundran Territories into launching a pre-emptive attack on the Western Frontier. Xylvania plays the true antagonist in the second game, luring the Anglo Isles to attack the Solar Empire based on rumors of a super-weapon.
In Japan the Battalion Wars series is considered to be part of the Famicom Wars series.