In a BJT there are three terminals i.e Base, Emitter and collector.
For amplifying the signal transistor need proper biasing of a transistor and for proper biasing we have to make the emitter base (EB) junction forward bias by providing minimum voltage to the base-Emitter junction(0.7 for Si and 0.3 for Ge) and also have to make the collector -Base junction reverse bias by setting minimum voltage to the voltage to the collector-Base (CB) junction(i.e 1V for Si and 0.7 for Ge) .

1>Making the EB junction forward bias means that there is a flow of current it means that resistance is low so i think this circuit is considered as the low resistance circuit.Emitter-Base junction is called as the low resistance circuit.

2>Making the CB junction reverse bias means that there is no/very less flow of current it means that resistance is high so i think this circuit is considered as the high resistance circuit. Finally, Collector-Base junction is called as the high resistance junction.

So Emitter- Base junction is termed as low resistance and Collector-Base junction is termed as the high resistance junction.
i think this make your doubt clear about you asked.