It has the same purpose as a NAT Instance but instead, this has much less configuration, higher bandwidth and better availability.
You are charged for creating and using a NAT gateway in your account.
Each NAT gateway is created in a specific Availability Zone and implemented with redundancy in that zone.
To create an Availability Zone-independent architecture, create a NAT gateway in each Availability Zone and configure your routing to ensure that resources use the NAT gateway in the same Availability Zone.
NAT gateway vs NAT instance
NAT gateways in each Availability Zone are implemented with redundancy.
Use a script to manage failover between instances.
Can scale up to 45 Gbps.
Depends on the instance type.
Managed by AWS.
Managed by you.
Software is optimized for handling NAT traffic.
A generic Amazon Linux AMI that's configured to perform NAT.