Can someone break down differences between mma, k-1, and normal kickboxing?

Question

especially rules concerning these: fighting on the ground, submission holds, and elbow strikes

Answer 1

MMA was originally a concept of pitting different fighting styles and seeing which one came out on top.  Now fighters train in all aspects: striking, standup-grappling, and ground-fighting.  Different promotions allow different things, but generally things that are banned include groin strikes, eye gouges, fish-hooking and strikes to the back of the head.

K-1 is Japanese fight promotion that allows any stand-up striking style, minus elbows.

Kickboxing is a combat sport that uses the hands and feet, but not the knees and elbows.

Answer 2

UFC is a MMA company that combines Brazilian Jui Jitsu, striking, grappling, wrestling, etc.  Uses a cage instead of a ring, has 5 minute rounds, 155, 170, 205, heavyweight divisions, does not allow knees on the ground.  Uses small gloves with fingers exposed for grappling purposes.  "Normal" kickboxing uses regular boxing gloves, no elbows, no knees, 3 minute rounds, 10 point scoring system, and up to 12 rounds.  K-1 is suppose to be a combination of Karate, Kempo, and other martial arts but it looks like regular kickboxing to me with the addition of Muay Thai clinch knee strikes.  Its Japanese based with three 3 minute rounds per contest.  Some K-1 cards had Cung Le fights which used special Sansho rules that allows points for takedowns and throws.  K-1 also had some standard MMA fights in the past.