Hi there, the biggest difference you’ll see is more capability in debugging your outputs and views in the HTTP Client snap, we mostly see it as a replacement for the REST Post/Get/etc snaps and will likely set those for deprecation once a few more things are added to the HTTP Client snap. The HTTP Entity (which you’ve highlighted) is the body content that you plan to send to the endpoint, this supports multipart and form data with multipart (which we previously supported in the REST snap pack), but now also supports x-www-form-urlencoded data as well as raw and binary data being send to the endpoint. When you select the entity type, you’ll see the UI dynamically change to show the inputs for those entity types, but that’s more likely to be useful in the REST Post/Put/Patch than Get.
Much of this has been pulled from the enhancements we’ve previously made to the REST Snap pack, but the goal with HTTP Client is to have it all in a single snap. We’ve also updated the accounts (yes, you’ll have to re-set them up) to better align with what we see as the most common accounts and make that process easier to use (including a generic Headers account for any headers that you wish to use for authorization).