1.As means in the role of.
Pattern 1: verb + as + noun
She is a trained teacher, but she works as a secretary in our office.
Typical verbs used before as:
act, serve, substitute, volunteer, work
Pattern 2: verb + noun + as + noun
We have selected you as the captain of the team.
choose, elect, nominate, pick, select, use
as for me—regarding me
They all went to the movies; as for me, I stayed home.