What is the advantage of using 2 or more capacitors in parallel in circuits instead of one larger capacitor?

Answer 1

When capacitors are connected in parallel, you add up their capacitances to obtain the overall capacitance of that 'bank'. The main reason for using two capacitors in parallel when decoupling, is that they have a lower overall inductance (electrical resistance in essence) to one large capacitor, which improves the decoupling effect. Using two capacitors also provides better high-frequency filtering for the power bus. One minor advantage of this, is that, you can obtain a certain redundancy when using two smaller capacitors in parallel, instead of only one, as if one capacitor fails, the other still acts to decouple the circuit, to a certain extent. Source: http://www.cvel.clemson.edu/emc/tutorials/Decoupling/decoupling01.html (this article uses other sources to back up their statements)

Answer 2

The advantage of using two or more capacitors in parallel instead of one larger capacitor is that the sum of capacitance in series is given by CTotal=c1+c2+. . .+cn.

So if they are two in parallel, their sum can give a larger value than connecting just one in parallel.