I've studied electronics for three years now, and I feel I have a decent knowledge of how most of things works.
However, there is one thing that I just can't understand quite...
Why do electronics, like computers, get slow and faulty after a couple years of use?
For example, I have this router. It has been running 24/7 for a couple of years now, but recently it started to be a little buggy, like not detecting a connection on some of the ports, etc.
Similar things happens to old computers, they get slow and hardware get faulty.
Why is this?
If I had a simple circuit with a power supply and a resistor running 24/7 for, say, a year, what would start to happen?