What is JSON and why is it used in APIs?

Updated Apr 28, 2026

Short answer

JavaScript Object Notation is a lightweight data-interchange format that is easy for humans to read/write and machines to parse.

Deep explanation

API Design at the junior level focuses on standards and communication. JavaScript Object Notation is a lightweight data-interchange format that is easy for humans to read/write and machines to parse. Following REST constraints ensures interoperability and ease of use.

Real-world example

A weather app fetching current temperature from a remote server.

Common mistakes

  • Using GET for operations that modify data.

Follow-up questions

  • What is a 201 status code?

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