What do the different tube amp types mean?

These are the choices we have in tube amplifier.
Topology in circuitry;
**single ended,
** tubes used,DHT/indirectly heated,,, like 300b,kt88,,211,,845.
*push-pull,
**tube used DHT or not DHT,,300b,,kt88
*OTL,
3 types of topology of tube OTL
** tube used,,,like 300b,211 0r 6as7,6c33c,7242 kt88,etc.
***different tubes used in one of these amps have different sound and over 1000 combinations/sounds.