Why is the background-color more dark on p element than in h2 header ?

Question

applied background to both h2, p element using css but i noticed the background is more dark in p than in h2 ? any reasons for that ? please explain me thank you :)
https://code.sololearn.com/Wvi4vZ5iyBqR/?ref=app

Answer 1

thanks. now i understand. i learned this somewhere that you can leave some tags unclosed so i assumed h2 was included in it so left it unclosed.