Conductance is the ability of any material to let electric current flow. Basically it is the inverse of resistance, and it is mathematically expressed as such:
S = 1 / R
Where S is conductance expressed by the unit Siemens.
For a parallel circuit, the conductance equivalent is:
St = S1 + S2 + S3
What this equation means is that the conductance of the overall circuit will always be higher than any of the components alone.
A higher conductance means the circuit will draw more current, and if you take a look at Ohm's law (I = V / R), you can see that the only way for current to be higher given a constant voltage is resistance being lower.
