An Elastic IP address is a static IP address designed for dynamic cloud computing. With an Elastic IP address, you can mask the failure of an instance or software by rapidly remapping the address to another instance in your account.
ELB stands for Elastic Load Balancers. These are used when you are expecting a huge spike of traffic to your website (say from a TV ad) and they allow you to balance the traffic across several servers to as to no overwhelm your single server.
Route 53 is Amazon’s DNS service. It allows you to point where certain URL’s are supposed to be. Leveraging Route 53 on Amazon is beneficial because Amazon has incredible uptime and is typically very reliable.
Cloudfront is Amazon’s CDN, also known as content distribution network. It makes it such that your data loads fast since it’s distributed across Amazon’s network as opposed to all being pulled from a single server.