I'm very new to AWS, so apologise if I am asking what might be a ridiculous question.
I am trying to understand more about security groups. Based of what I found from reading various documentations... what I understand (not sure if im right) is there are two types of security groups. One is EC2-VPC which is an EC2 security group type and another is a VPC Security group. We can attach these security group types to other aws services such as ELB/NLB,S3 etc...am I wrong?
Also came across a RDS security group. Is that a different type of security group? How many types of security groups are there? How do I find out which type of security group is attached to an aws service?
There is only one type of security group in AWS. You can view them from the EC2 console in addition to the VPC console simply due to legacy reasons where some features of EC2 networking existed in AWS before VPCs existed.
Security groups can be assigned to EC2 instances, Fargate instances, load balancers, RDS instances, etc.. A single security group can even be assigned to multiple resources of different types. Basically, any AWS service that runs in a VPC will require you to assign a security group to the resources it creates in the VPC.