There are multiple options to create REST APIs to expose Salesforce data and processes, some of the popular ones being -
Directly use Object APIs Use composite APIs: Tie multiple APIs together in one call.
If you always wanted to learn salesforce.com APIs and what you could do with them, but too afraid to ask.. fear not - now that we have example API collection directly from salesforce!
JSON Web Token, or JWT, is a way to enable authentication and get you access to a resource. It is a digitally signed token that can be used for authentication across parties, and is a self-contained way to transfer information and include claims to specified resources.
Salesforce changed the way files are managed with Lightning Spring 17 release, and this introduced a more elaborate procedure to reach the files from external systems. The API call is not as straight-forward as retrieving the ‘body’ to get file content (which was the case earlier).
Rest APIs are quite easy to use and my preferred way to get things done. This post outlines how you can enable your SFDC instance to accept REST calls, and demonstrates fetching the data using Postman .