Other forms: consultancies
If it's your job to give advice about how to run a lemonade stand, you've started your own lemonade-selling consultancy, or a business that gives expert information about a particular field.
Most consultancies have to do with the business world, as when a company that's trying to avoid harming the environment hires an environmental consultancy to provide expert tips about how to be more environmentally friendly. But any firm that's in the business of giving advice — whether to governments or schools or sports teams — can be described as a consultancy.