Licenses are based on the number of developers and the number of domains where the library will be used. We offer two sizes of developer licenses: single or up to ten developers. We offer three sizes of location licenses: single, up to 10 and unlimited domains. A developer might be a software developer, a systems administrator or any other person who uses the product. Note that subdomains are considered different domains, eg. contoso.com and sub.contoso.com are counted as two.
As your needs grow, you can upgrade to a higher level license by simply paying the difference in license costs. Whenever you need to upgrade to a higher license, you can see your upgrade options on Upgrade page.