There are 2 kinds of communication that we can use from a client to a server. One is Rest API and the other is WebSocket API .
Rest API is when a client sends a request to the server and receives a response back from the server. The data can be in the XML or Json format. Possible http methods are put, post, get, patch or delete.
WebSocket supports 2 way communication.
API Gateway. Manager your API's with versions. Handle increased traffic gracefully. Setup authentication and authorization.
Resilency
Set number of requests per second.
Stage
Can set cache and throttle settings.
Monitoring API with cloudwatch
Every minute the API Gateway sends the following data to cloudwatch.
1) Count total number of API requests made in a given period.
2) Latency
3) Cache hit count
4) Cache hit miss
5) Http 400 and 500 errors
Secure Access to API
1) IAM Permissions
a) Create the API , deploy
b) To invoke the API
2) Resource policy
Who can invoke my API
3) Lambda Authorizerthorizers