RNA interference is a mechanism of eukaryotic gene regulation. In this mechanism, the enzyme “dicer” cuts dsRNA into smaller fragments called siRNA, which form a complex with RISC and degrade specific RNA.
siRNA or small interfering RNA as a part of RISC complex finds and binds to complementary mRNA and it induces the cleavage of mRNA. This causes degradation of that mRNA. This is the way RNA interference prevents translation.