IEC 60062 is a set of rules that grown-ups have made to help us understand the different values of electronic components, such as resistors, capacitors and diodes. It helps us know how much electricity these components can take before they break, and how much they can resist the flow of electricity.
It's like when you play with your toy cars and you have to find the right track for them to race on. Just like you have to make sure the track is the right length and width for your cars to race, electronic components need to be the right size to fit in their place and do their job properly. IEC 60062 gives us a way to make sure all the electronic components are the right size and work the way they should.