In Five Nights at Freddy's Remaster, you play as Mike Schmidt and have to beat Freddy Fazbear and his friends over the course of five nights.
As a security guard at Freddy Fazzbear's Pizzeria, you have to make it through all five nights (one shift per night) without getting killed by the animatronics that come to life at night and become violent. This is why no one can do this job for long.
To do this, make sure the electricity stays on and open and close doors on both sides, left and right. You can also turn lights on and off and move the security cams around to find the monsters.
When you see them creeping up on you, make sure the doors are locked until morning, when you will be safe. Repeat that for five nights.
Have fun and good luck!