Difference between esrecurse and estraverse

Hello!
First of all, thank you for great tools. I have general questions regarding estools.

1. What are the differences between [esrecurse](https://github.com/estools/esrecurse) and [estraverse](https://github.com/estools/estraverse)? 
2. What are the best use-cases for each tool?

Thanks in advance!

