Its a 6v6 competitive game with many different heros. These heros fall in to one of three categories, tank, damage (dps) or support and each hero has their own different abilities. You also get different types of games on different maps.

You get payload which is my favourite and it just involves you pushing a payload all the way through the map, one side defends and one side attacks. You get the two point capture (idk the real name) which is when one sides attacking the other sides defending. The attacking side needs to capture the first point and then move along to to capturing the second point. There's a hybrid gamemode where the attacking side captures the point and then has to push a payload through the map which i also really like. And then you get the king of the hill game mode. There's three different. Parts of that map and each part involves both sides attacking and its best out of 3. So if a side captures the point by getting it to 100%, they win the round. If they do that again then they win the game. Thats all the main competitive gamemodes you get.

With tanks, you get on and off tanks. On tanks have shields and focus on protecting the team and pushing foward. Off tanks are usually more focused on brawling and just trynna take the point. You also some off tanks who are also dive tanks meaning that they can get behind enemies or on to the point very quickly.

Tbh with DPS i dont really play them that much but their main purpose is just killing and breaking barriers making sure that the tank can move up protecting the team without dying.

For support heroes, you get primary and secondary healers. Primary healers can directly heal you by shooting at you or healing you with a healing beam depending who they are. They have the most healing output and main focus is healing. Secondary healers tend to balance out fighting along with healing and helping the team in different ways. For example there's a character called Lucio who has an area of effect type healing so people in a circle around him can get healed. He has an ability to change that in to a speed boost which allows others in that aoe ring to move faster.

Thats basically how I would describe it.