situation vs line of work

situation and line of work both are nouns.

Word	Noun	Adjective	Verb	Adverb
situation	Yes	No	No	No
line of work	Yes	No	No	No

As nouns, line of work is a hypernym of situation; that is, line of work is a word with a broader meaning than situation:

Other hypernyms of situation include business, job, line, occupation.

situation (noun)	line of work (noun)
a job in an organization	the principal activity in your life that you do to earn money
physical position in relation to the surroundings
the general state of things; the combination of circumstances at a given time
a condition or position in which you find yourself
a complex or critical or unusual difficulty