The glossary includes definitions for terms which are commonly used here, and that are part of the DDS and RTI lexicon.

A sample is a single data update received over DDS. "I received a sample of Track Data."
2961 reads — 0 comments
A Topic is the most basic description of data to be published or subscribed to. Each Topic describes a data stream in your system. A Topic is identified by its name, which is a string that must be unique in the whole Domain.
1478 reads — 0 comments
This generally refers to a lower-layer mechanism for transmitting data. Typically a transport is a type of network communication layer that RTI Connext DDS sends data on top of, but this could also be shared memory or another type of bus. Transports may also be stackable - so a transport may not be
7264 reads — 0 comments