what is the main difference between spit and sliva? they are same , why it has different names i.e. saliva and spit

answer plz

Spit/spitting is the projection of saliva from the submandibular gland upon compression by the tongue.

Spitting or expectoration is the act of forcibly ejecting saliva or other substances from the mouth.

Saliva is the watery substance produced in the mouths of humans and most animals. Saliva is a component of oral fluid. In mammals, saliva is produced in and secreted from the three pairs of major salivary glands: the parotid, sublingual, and submandibular glands. 

they are not the same because when we spit,many of the other substances such as germs food materials go out with the saliva

but saliva is a fluid or a watery substance produced in the mouth the saliva is secreated by the major salivary glands

-pataroid gland,sublingual glands,and the submaxilliary glands