Authentication and authorization, often referred to collectively as "auth," are crucial yet complex components of software development that involve verifying user identities and determining access permissions. The complexity of implementing these processes often arises from the multitude of available methods and technologies, such as JWT tokens, OAuth2, and cookies, which each have their own advantages and limitations depending on the application type. Single-page applications (SPAs), server-side rendering (SSR), and native applications each require specific strategies for handling sessions, with storage options like cookies and Web Workers offering different levels of security and accessibility. For browser-based applications, cookies with the httpOnly attribute are often preferred due to their secure and efficient management of session data, while server-side and native applications can rely on tokens stored in memory or secure storage. Ultimately, there is no one-size-fits-all solution, and developers must carefully evaluate their specific requirements and security practices to choose the most appropriate authentication method for their application, with resources like OWASP providing valuable guidance.