Aperture :
Aperture is how big or small the iris is , it is measured in f-stops such as 2.8 , 4 , 5.6 , 8 , 11 , 16 and 22 the lower the aperture eg; 2.8 the bigger the iris will be, this means that you will get a shallow depth of field what this means is that you will get a slightly blurred background on the other side the higher the aperture like 22 the smaller the iris will be , this means that you will get a great depth of field what this means is that all of your photo will be sharp.
Aperture is how big or small the iris is , it is measured in f-stops such as 2.8 , 4 , 5.6 , 8 , 11 , 16 and 22 the lower the aperture eg; 2.8 the bigger the iris will be, this means that you will get a shallow depth of field what this means is that you will get a slightly blurred background on the other side the higher the aperture like 22 the smaller the iris will be , this means that you will get a great depth of field what this means is that all of your photo will be sharp.
This picture has got an aperture of 4 , this is why it has got a shallow depth of field and thats the reason it has a blurred background
This picture has got an aperture of 15 , this is why it has got a great depth of field and thats the reason its background is sharp and in focus