What are AWS Security Groups used for?

AWS Security Groups are utilized to act as virtual firewalls for AWS resources, specifically for instances running within Amazon EC2. They serve to regulate inbound and outbound traffic to these resources by allowing users to define rules that specify permitted protocols, ports, and source/destination IP addresses. This enhances security by controlling which network traffic is allowed to reach the associated resources.

Security Groups are stateful, meaning that if you allow an incoming request from an IP address, the response can automatically return to that IP without needing an explicit rule for the outbound response. This simplifies managing access to your resources while providing flexibility in defining security policies.

The other options represent different aspects of AWS functionality. Managing user permissions pertains to AWS Identity and Access Management (IAM), not Security Groups. Controlling access to AWS accounts is also a broader IAM function that involves user and role management rather than traffic filtering. Monitoring network latency is a task typically handled by other AWS monitoring tools and services, not by Security Groups, which focus explicitly on traffic control.