Boulders (or Talus) is really scree, just a lot larger version. People just tend to call smaller bits of rock Scree and bigger bits Boulders. It’s all the fragments that have broken off of mountains and piled up. Depending on the composition of the original rock, the pieces of talus will be tiny, huge, or somewhere in between.
Out of all the hiking I have done, this is my favourite style of hiking. It can be dangerous and takes a lot of effort, but when things are just right, you feel just like a wild mountain goat scampering wherever you want to go.
Boulder hopping is when you step or hop from one boulder to the next in a large field of (you guessed it) boulders. In good hiking boots with grippy rubber soles and on dry rocks this is fun. Instead of working your way between the boulders, you simply step on the tops of them.
With a bit of practice you will build confidence in your ability and footing and can practically dance across a boulder field. Foot-eye coordination is key so that you know where you are heading, where you are landing and have the next couple of steps already planned ahead. I usually hop back and forth when descending a steeper field because the change in direction helps slow me down and maintain control.
Don’t even try rock hopping if it is raining, or your boots are wet, or its cold enough for ice. Any slippery surface will be disastrous.