What is a headshot?
A headshot typically means a portrait of a person showing their head and shoulders. Sometimes called a 'head and shoulders' portrait or a profile portrait.
Clients sometimes ask for a 3/4 length portrait or even full length. This is something to discuss on first contact.
Other things to consider are 'style' of the headshot.
This means a headshot portrait in a studio environment, with a plain background and strobe lights. As a photographer I would bring these to a clients office but can also be shot in a physical studio. The lighting can be fairly 'traditional' or you can go a little edgy- something that would be discussed before hand.
Office Headshot / Environmental portrait
This would be a headshot shot in and around the office, working environment or factory. One could have the background of the portrait featuring the office space, choose an interesting wall or area. You may also want to throw the background out of focus to give a suggestion of the office without it being to literal.
See office headshots
Headshot portraits outside
This is often a great solution. Not every office is favourable to photography or has the space so going outside is a nice option. It can feature the area of your business which could be nice to show. I like to use a shallow depth of field and have a soft backgrond like the example here.