EC2 lets you rent a computer in the cloud instead of buying and maintaining your own physical server...which is higher on price...

You need a key pair when launching a Linux EC2 instance because it’s required for SSH access. When using EC2 Instance Connect, you don’t need the .pem file, as the Linux machine can be accessed through the browser. The .pem key is only required when connecting to the EC2 Linux instance using an SSH client.

We should deploy applications across multiple AWS Availability Zones so that if one Availability Zone goes down, the application remains accessible from another, ensuring uninterrupted service to customers