Introduce to others
In China, there are many strict conventional rules on introduction to others:
a. The junior should be introduced to the senior first;
b. The male should be introduced to the female first;
c. The inferior should be introduced to the superior first;
d. The host should be introduced to the guest first.
These ways of introduction is to show high respect to the senior, the female, the superior and the guest. However, if you are in a generally more informal occasion, the introduction to others can be less ceremonious.