Both MEAN and MERN stacks leverage Node.js for server-side
operations, enabling scalable and efficient execution of JavaScript beyond the
confines of the browser. While MEAN excels in handling complex applications
with Angular's rich feature set, MERN prioritizes flexibility and simplicity
through React's approach. Ultimately, the decision between MEAN and MERN hinges
on project requirements, developer expertise, and preferences regarding
comprehensive frameworks versus streamlined libraries. MEAN Stack Vs MERN Stack
are both formidable options, offering developers a rich toolkit to build
cutting-edge web applications.

https://infostans.com/mean-stack-vs-mern-stack/

Mean Stack vs Mern Stack: A Comprehensive Guide