First Of all I'll tell you About its Features and Specifications Vivo y21's Specification are
It has 1 gb of Ram. Thats enough if you are just using facebook and whatsapp and couple of games etc so that will be enough.
Because it has 1.4ghz of Quad core processor.
And vivo y21 runs on lollipop of android.
And 5 mp of camera of rear and 2 mp front.
But the most amazing thing is its camera is Fantastic.you can see my dp of mouthshut account to see the quality of picture.
And it has lots of inbuilt features so you dont have to download other apps like. Booster or applock etc and it has super saver mode in it for long battery backup. And 16gb of Rom too
In short it got What you looking for.