DVB-H stands for Digital Video Broadcasting: Handhelds and is basically an extenstion to older DVB-T standard.
DVB-H is a terrestial digital TV standard that uses less power in receiving client than its big brother, DVB-T, and allows the receiving device to move freely while receiving the transmission, thus making it ideal for mobile phones and haldheld computers to receive digital TV broadcasting over the digiTV network (without using mobile phone networks at all).
As it is really just an extension to DVB-T, DVB-H uses the same specs as its older brother. Video is normally encoded with MPEG-2 (but can be encoded with MPEG-1 as well, although very rarely used) and the standard, just like its other siblings DVB-C, DVB-S and DVB-T, is mostly used in Europe.
DVB-H was formerly known as DVB-X.