About Globus Accounts
As a first-time user, it is worth knowing a little bit about how Globus handles identities and authentication.
Globus recognizes that many people have multiple accounts, not just the account at their primary institution. For example, if you do work at CERN, then you probably have a CERN account. Globus refers to these accounts as identities. The first time you log in to Globus, the account you use to log in will be your primary identity; once logged in, you can add linked identities, one for each account at other institutions.
In the example, Karl (who works at Stanford) first logged into Globus using his Stanford credentials, but later he added his account at The Ohio State University, and his personal email address, as linked identities. Karl was able to add his personal email address because he has a Google account.
Karl can now log in to Globus using his Ohio State or Google accounts, in addition to his Stanford account. If someone wants to share something with Karl, or add him to a group, they can do so using any of his linked email addresses (not just his Stanford address).
Got an XSEDE Allocation?
If you have access to any XSEDE resources, you should link your XSEDE account. All XSEDE clusters use XSEDE accounts for authentication.
For people without any institutional affiliation (or, at least, any institution that Globus recognizes), you can get a Globus ID. It is mainly used for entities do not have a normal institutional account (like an entire group), and for software leveraging the Globus infrastructure. It is also the last-resort option if you want to link a personal email address.
Google, ORCID, United ID
If you have an account with one of these services—even if you registered with your personal email address—you can link them. This is preferable to creating a Globus ID.
Globus IDs for entities are covered more in the Globus ID page.