A "job" is an official activity, you sign up a contract, perform tasks and get salary. "Work" has more general meaning. You can work both for your employer (I work at the bank) and for yourself (he's working in his garden now). We also use "work", when we mean a place where we have a job: - I'm at work - I go to work at 8. I hope that now the difference is clearer for you!

"Work" is the correct word, but the preposition should be "at", not "in". Also, as “work” is usually uncountable in this context (unlike "job", which is countable), it would be natural not to use any determiners. We could easily say “at work” in this context, but not "*in my work" (in this context).

Hi! You can say both "new possition at my job" and "new position at work" in that context (the second option would not be formal). You do your job to earn money, job is a specific occupation such as teacher, lawyer, etc. Term "work" is more general, you work at your job but you also work on an art piece, you work on a school project etc. But mostly the two terms are pretty simillar. I believe that "work" is more commonly used than "job", given that it is more general. I hope this helped.

Oops. I meant to say I would NOT use “job”in this context. Sorry.

You could say “I’ve been offered a new position at work.” I’ve heard that said frequently said by native speakers. You have to leave the “my” out is all if you say it that way. That actually sounds a bit more natural and standard, where “job” always sounded colloquial to me. I really would use job in this context.