"HAS" is the third person singular present tense of "HAVE". This basically means that it is used when you are speaking in the third person singular, alongside the pronouns "HE, SHE and IT".
This phone has more features than my old one.
She has this terrible back pain from yesterday.
She has this great idea.... I'm not convinced it's a good plan.
Marvin has my Electric saw
"Has" and "have" are both present tense conjugations of the verb "to have," we use "has" or "have" depending on the subject.
If the subject is 3rd person, singular, then you use "has." All other subjects take on the irregular verb "have".
1st Person I have We have
2nd Person You have You have
3rd Person He/She/it has They have