An Entity refers to any company that intends on sending messages to their end customers as a form of communication.
A telemarketer refers to a company that intends on facilitating the sending of messages on behalf of a company by way of providing services of SMS triggering via application or API to their customers.
Here's an example to explain how these two are different.
For example, all the customers that sign up with Kaleyra to use the SMS services to trigger messages to their end customers are the “Entity”.
Kaleyra can be taken as the easiest example for a telemarketer, where we enable our customers who sign up, by providing the SMS service that they require, through our platform.