Streaming is the transfer of the captured data from the device. Once stream is started, it will continue to capture data until the stream is stopped. All samples in stream packets are guaranteed to be contiguous, but there may be gaps between packets due to bottlenecks in network traffic.
Block mode captures are single one-time captures, where all samples in the packets are garanteed to be contiguious, and all packets are contiguous so no gaps in block mode.
Sweeping is a series of block mode captures where the receiver automatically steps to the next sweep frequency and performs a block mode capture of the configured size.
Sweeping is the same as scanning. This refers to the IBW window sweeping across frequency range of interest.