>>716529756 (OP)CoD = everyone plays solo and everything is fast-paced and constantly run'n'gun on small maps with smaller player numbers, usually just 6v6. Most guns are usually like lasers with barely any recoil and everything is hitscan. Movement is usually super fast to satisfy ADHD-riddled players.
BF = most people attempt to play as a team, things are usually more slow and methodical, maps are MUCH bigger and usually includes ground and air vehicles with player numbers up towards 128 in total. Most guns usually have some kind of recoil pattern and a lot of weapons are projectile based. Movement is usually more realistic.