Merriam Webster says, “collect: to get things from different places and bring them together”
THE ‘collect’ COMMAND
The ‘collect’ command is used to replicate data from one index into another. The assumed usage, and original intent, of this command is to aggregate granular events into a summary index. In fact, the documentation states that is its purpose in the Synopsis – “Put search results into a summary index.” But that need not always be the case. There are other uses for the ‘collect’ command, as well – result sets can be collected at either a granular or aggregate (summary) level. And they may be retained in regular or summary indexes.
There are no licensing implications to duplicating the data in another index – after the original data is indexed, it is not counted again …