If you have recently started out in business or have not done much marketing in the past, you may not have a logo. A logo is often an image or text or combination of that tells people a bit about what your business is. You may have your company name is your logo or an abbreviation of it. Some brands start off with using their company name in their logo and as their brand builds up and they become more widely recognised, they then might drop their name in favour of just an image. An example of this is McDonalds who often now only have a yellow “m” on a red background.
You should ideally use a graphic designer to create your logo for you as they will not only be able to provide it to you in many different formats but they will also be able to give you a few different options to choose from. They may give you the logo with inverted colours so that you can use it on a white and black background. Logo design costs from around £200 but you may find it cheaper if you are willing to use someone that doesn’t have as much experience.