AWS account 

This is the account that you create when you first sign up for AWS. It is also known as a root account in AWS terminology. This root account has a username as your email address and password that you use with this username. These credentials are used to log into your AWS account through the AWS Management Console, a web application to manage your AWS resources. This root account has administrator access for all AWS services, hence AWS does not recommend using root account credentials for day-to-day interactions with AWS; instead, they recommend creating another user with the required privileges to perform those activities. In some cases, your organization might decide to use multiple AWS accounts, one for each department or entity for example, and then create IAM users within each of the AWS accounts for the appropriate people and resources. 

Let us look at the following scenarios for choosing strategies for AWS account creation:

Table 3 - AWS account strategies

Having multiple AWS accounts also helps in decreasing your blast radius and reducing your disaster recovery time. So if there is something wrong with one AWS account, the impact will be minimal on running business operations, as other accounts will be working as usual along with their resources. Having multiple AWS accounts also increases security by segregating your resources across accounts based on the principle of least privilege.