This is the 1908th most frequent Polish word.
s
In Polish, "s" means "with."
In this sentence, 'z' serves as a preposition meaning 'with', indicating association or accompaniment.
On jest z nauczycielką.
He is with the teacher.
Here, 'z rana' implies a time expression literally meaning 'from morning', used idiomatically to mean 'in the morning'.
Słońce wschodzi z rana.
The sun rises in the morning.
'Z łatwością' uses 'z' to express the manner or means of the action, indicating 'with'.