Aperture:

Aperture is basically how big the hole is where the light goes through.

The SMALLER the number the bigger the hole and the LARGER the number

the smaller the hole.

* The SHORTER the depth of field ,, the background is blurry.

*The DEEPER the depth of field,, the background stays in fosus.

-- f2 is considered a larger aperture

-- f 22 would be the smaller aperture and will not blurr the background.