Consulting can have a zillion meanings and be in bazillion different areas and is used as a bucket term. Basically it means you have a speciality in some area that a company needs help with, they bring you in as a non-employee to help them with a specific project, effort or problem they have. You are not on their staff however. Firms will also use a consultant if they have a specialty short term project/need and dont want to be put someone on staff with that knowledge for it.

Some consultants work on one project at a time and devote months to that project, others, like myself, juggle many projects at a time and are with a given client for a couple days and then go see the next and rotate between them.

Why do we have to be on site (travel to them) it is not always necessary (I do a lot with clients by webex) but a lot of work involves meetings with key people in the company, working on systems that are already at the client, doing training with staff of the company and so on, that you have to be there for.

Hope this helps!

BTW to the OP who is going to travel for work, be ready for the impact it will have on your friendships and relationships, you will lose a number of them if you are gone all the time. I wasn't prepared for this change when I started. Other people's lives still go on while you arent around and you fall out of the loop really quickly *frown*