API Security Academy
OWASP API Top 10
OWASP compiled a top 10 API security issues list to bring awareness to the most common attack vectors that attackers can use to compromise information or bring down the API. They have made this list available to the public so that you can learn about what to be wary of and how to increase the security around your API.
API Security 101
Application security is the discipline of applying sound security principles to protect the confidentiality, integrity, and availability of software applications and their data. There are several types of software applications, such as web, mobile, native clients (i.e Windows Store apps), and command line. Each type of application has a different threat model and must apply different principles and tactics to secure it.