All mobile suits are divided into the two factions of the game. The Earth Federation and Zeon. From there they are broken into 3 additional groups. Each of which are strong against one type while being weak against another.
There is a large diversity in how they play, however they are generally geared towards close-ranged melee combat. Without the use of custom parts, these suits are usually severely lacking in defensive stats outside of their melee defense stats. Due to this many players chose to simply max out their defensive melee stats to act as a sort of counter to other enemy melee suits as opposed to ignoring their melee defense and simply giving the suit a nice balance between its ballistic defense and beam defense. Both methods are viable, it is simply a matter of how you want to build your team and whether you like to be aggressive or more of a team oriented player. Red/Close-Combat suits are strong against Yellow/Support suits and weak against the Blue/Balance suits. Play with caution.
Like the name implies, these suits are well rounded with their stats, melee, and fire-power. Easily the most commonly faced mobile suit because of how versatile they can be. Because of this though, they do not shine in any one area. They are jacks of all trades but masters of none. With that said, there are some of them that are pretty beefy and can be used to help tank damage to protect your team. They are strong against Red/Melee Suits but weak against the Yellow/Support suits.
These suits, for the most part, are best suited for supporting other suits in combat while staying at a distance of around 500m~700m away. While the range and fire-power are the main draws for using support types, keep in mind that they tend to have weaker defense values especially against melee weapons. They are strong against Blue/Balance suits and weak against Red/Melee Suits.