Rape is sex without consent, i.e. one of the partners does not want the activity. There are various laws that govern under which circumstances this is punishable, often quite severely. Women who have been raped often have trouble talking about this and should contact an organization specialised in supporting them as soon as possible.
Rape is when someone has sex with another person but the other person doesn't want to have it. And sex is when a guy and a girl get in bed together and kiss and hug then the guy would put his penis in the girls vagina to make a baby.