PAGE Web Services: When a page is exposed as a Web service, a default set of operations is exposed to developers so that they can manage COMMON record handling operations such as Create, READ, Update, and Delete. Page-based Web services offer built-in optimistic CONCURRENCY management. Each operation call in a page-based Web service is managed as a single TRANSACTION.

Codeunit Web Services: Codeunit Web services provide you with the most control and flexibility. When a codeunit is exposed as a Web service, no default set of operations is exposed. You can decide which operations are available on a codeunit.

Page Web Services: When a page is exposed as a Web service, a default set of operations is exposed to developers so that they can manage common record handling operations such as Create, Read, Update, and Delete. Page-based Web services offer built-in optimistic concurrency management. Each operation call in a page-based Web service is managed as a single transaction.

Codeunit Web Services: Codeunit Web services provide you with the most control and flexibility. When a codeunit is exposed as a Web service, no default set of operations is exposed. You can decide which operations are available on a codeunit.