
Token-based authentication and access control is the standard security architecture for modern API-backed applications. Writing clients for such architectures requires some knowledge around how to request, manage and use those tokens.
Depending on the type of client (browser-based vs native) you take slightly different approaches and can take advantage of different features of the protocols. Brock and Dominick are both authors of client libraries that make your life easier when building modern front-ends and want to share what they have learned while building them.