There are a few different types of usability testing or reasons to conduct usability research:

• Comparative Usability Testing. Used to compare the usability of one website with another. Comparative tests are commonly used to compare a website against peer or competitor sites, however it can also be used to compare two designs to establish which provides the best user experience.
• Explorative Usability Testing. Before a new product is released, explorative usability testing can establish what content and functionality a new product should include to meet the needs of its users. Users test a range of different services where they are given realistic scenarios to complete which helps to highlight any gaps in the market that can be taken advantage of and illustrate where to focus design effort.