Authentication Tokens
Create Token using Simple Login Credentials
Generates a token using a straightforward JSON payload with separate fields (Account, User, Password, ClientName). Use this method when you want a direct login-style request without relying on OAuth libraries or grant types.
Create Token using OAuth-style Request
Generates a token using an OAuth-style client_credentials request with a combined Client_ID and Client_Secret. Use this method when you prefer OAuth-compatible behavior using OAuth flows and design patterns.
HMAC Authorization via SHA1 hashing
HMAC Authorization requires more overhead in making each API call but it does afford additional security via a one-way dynamically changing signature.
See HMAC Authorization Guide here