public servant vs employee

public servant and employee both are nouns.

Word	Noun	Adjective	Verb	Adverb
public servant	Yes	No	No	No
employee	Yes	No	No	No

As nouns, employee is a hypernym of public servant; that is, employee is a word with a broader meaning than public servant:

public servant: someone who holds a government position (either by election or appointment)
employee: a worker who is hired to perform a job

public servant (noun)	employee (noun)
someone who holds a government position (either by election or appointment)	a worker who is hired to perform a job