Ah, I understand the question now!
For me there are four types of bag, in two categories:
1. Non-photographic:
1.1 Briefcase
I have a small black Italian leather briefcase that is my normal, day to day office use carry-all. It takes my laptop and charger, and a small amount of paperwork. It has a detachable shoulder-strap and would not look out of place in any boardroom. Inside I have fitted a Billingham Hadley insert which enables me to use it as a camera bag when I want to carry kit while "on duty"
1.2 Shoulder bag
I carry a shoulder bag at weekends just because I like to keep my hands free. It is big enough for bits and pieces, and my camera of choice which sits loose in the main compartment, on top of a folded up dishdash.
2. Photographic
2.1 Small
This ranges from belt pouches up to a small Safrotto F803 type, or a Billingham Hadley Pro. Small enough to not get too heavy for a day's walking around. This is for dedicated shooting.
2.2. Large
Big Domke, LowePro backpack, etc. Long distance travel, or big kit portage.
Hope this helps.
Regards,
Bill