Each client class accepts a set of options when constructed, most of which are common to all clients. Options allows you to specify such details as credentials to use and retry strategies etc.
Each client has an accompanying options interface and class e.g. ISQSOptions and TSQSOptions respectively for use with the TSQSOptions class.
// Create "Options"
Options := TSQSOptions.Create;
// Set some options.
Options.RetryLimit := 5;
// Create the client.
SQS := TSQSClient.Create(Options);
Each "options" interface extends IAWSOptions which provides an interface for all the common AWS client options.
Configuration via options takes precedence over all other configuration sources.
Option classes like TSQSOptions typically accept another options instance allowing you to create variations of a common set of options.