For Magento to perform well, you’ll need Redis and Varnish.
- Redis is a distributed key-value store that is used to cache information coming from the database
- Varnish is a reverse caching proxy that is used to cache entire pages
Memcached, it performs the same role as Redis. Memcached is the predecessor of Redis and Redis has more features.
As far as Nginx is concerned, using activating it depends on the use case. I would use Nginx as a webserver and maybe even as a TLS proxy. But I wouldn’t use Nginx as a page cache.
After activating Redis & Varnish, please configure your Magento to properly connect with both.
Thank you.