BIGSERIAL vs SERIAL in PostgreSQL

Question

I'm new on PostgreSQL for auto-increment we have to use BIGSERIAL or SERIAL, so can anyone please explain which one we have to use when creating a table. Which one be the best please explain scenario wise.

Answer 1

From the docs:

serial      4 bytes     autoincrementing integer        1 to 2147483647
bigserial   8 bytes     large autoincrementing integer  1 to 9223372036854775807