What type of data format do RESTlets utilize for client-server communication?

RESTlets in NetSuite primarily utilize JSON as their data format for client-server communication. JSON (JavaScript Object Notation) is lightweight, easy to read and write, and well-suited for the data interchange between clients and servers. Its structure aligns well with JavaScript, making it particularly efficient in web applications where JavaScript is often used to parse the data.

JSON's simplicity allows for less bandwidth consumption compared to more verbose formats like XML, making it an optimal choice for RESTful services. This efficiency is critical in scenarios where performance and speed are crucial, such as real-time applications or mobile app interactions.

While other formats like HTML, XML, and CSV are utilized in various contexts, they do not match the effectiveness of JSON in the context of RESTlet communication in NetSuite. HTML is designed for document structure, XML is more complex and generally used for configurations or data representation that requires a schema, and CSV is a flat file format ideal for simple tabular data but lacks the hierarchical structure that JSON provides.