Why wont my tablet charge?

When my tablet got too low,i would plug it in. Eventually, it would start to go down.one day i put it in for the third time in a row when i looked to make sure it was charging and IT WASNT!!!!! WHATS WRONG WITH IT AND HOW DO I FIX IT!!!!!IM GOOD AT THIS STUFF AND I DONT EVEN KNOW HOW TO FIX IT!!!!!!!PLZ HELP!!!!! MY TABLET IS GONNA DIE SOON!!!!!FOREVER!!!!!!!!(if it doesnt get fixed)