The difference between ISO 27001 AND NESA

I'm assuming that by NESA you are referring to the National Electronic Security Authority from the United Arab Emirates (UAE). Considering that, NESA  is a government body that develops documents based on ISO 27001 and several other established standards (such as NIST publications). These documents are named as a whole as NESA Information Pack. On the other hand, ISO 27001 is an internationally recognized standard for information security management, published by ISO.

In short, ISO 27001 is an international standard, while NESA documents are developed based in part on ISO 27001, but to cover specifics of United Arab Emirates.

This article will provide you further explanation about ISO 27001:
- What is ISO 27001 https://advisera.com/27001academy/what-is-iso-27001/