How to assign permission using policies.

To assign permission there are 3 ways -

Import - To import an already managed policy within your account and customize it as per your needs. A managed policy can be both i.e an AWS one or customer managed one.

Visual Editor - To construct a new policy using visual editor i.e. to create from scratch. In case of editor knowledge of writing JSON is not required.

JSON - To create policy using JSON syntax. You can use an example of how to write a policy in JSON using link - example policy.