MPEG-2 Transport Stream
The MPEG-2 Transport Stream Format specifies how to encapsulate MPEG-2 Elementary Stream Packets, the MPEG-2 Multiplexer procedure, and how to add additional information like PSI Tables and Sync Information.
Normally, in DVB-T (and others?) a transport stream contains more than one program stream and therefore more than one program.
Multiple programs is a page describing various software solutions to record more than one program at a time.