Social Differences are based on two main factors :
(i) On the basis of accident of Birth.
(ii) On the basis of our choices.
Differences on the basis of Birth
(i) Normally we don't choose to belong to our community. We belong to it simply because we are born into it.
(ii) People around us, have different physical abilities or disabilities.
Differences on the basis of choices
Some of the social differences are based on our choices. For example,
(i) Some people are atheists. They don't believe in God or any religion.
(ii) Some people choose to follow a religion other than the one in which they are born.
(iii) Most of us choose what to study, which occupation to take up and which games or cultural activities to take part in.
All these lead to formation of social groups that are based on our choices.