Knick-knacks and trinkets.

Whats the difference between knick-knacks and trinkets? Someone told me that it's the "intention" in its design. Like they're similar but they only differ in that knick-knacks are like souvenirs whereas trinkets are broader. But I'm not convinced enough because when I googled the two words I found some differences in the definitions and what I personally took from the definitions is that trinkets are more like worthless/cheap small pieces of jewellery and knick-knacks are generally any small and worthless objects. Is this inference accurate?

Many thanks!