AWS account is a container for AWS resources. It provides a container for authentication, authorization and billing services. Whenever a new user sign up for AWS services a root account is created by default. Root user can create more IAM users for more granular access. In case account is compromised the blast radius is restricted to account itself. This is very important while setting up accounts for different line of businesses within same organization.
AWS account provides container for all AWS resources. It provides ability to authenticate and authorize user.It also helps to manage billing.