I am pretty new to AWS deployment (please send any helpful guides). And I read that it comes with an elastic load balancer but I've also heard that a lot of people put NGINX on an EC2 to use as a load balancer.
Do people commonly use either or? Having two seems redundant.
Nginx on an EC2 instance for load balancing would be a single point of failure, if the EC2 instance went down your app would be down. An AWS Load Balancer is actually multiple load balancer nodes distributed across multiple AWS availability zones to provide high availability. The EC2 instance would also be something for you to have to manage, where an AWS Load Balancer is managed for you by Amazon.
You mention Elastic Beanstalk in your question title. Elastic Beanstalk will use both. It uses a Load Balancer for distributing traffic across multiple instances, and it uses Nginx on each instance as a reverse proxy to your application.
