Indigo is the latest version. I recommend you use it unless you do have any specific package not available in Indigo. Go for Indigo.
Most of packages` documentation is ready for Indigo as well.
There will always be some leakages in documentation for latest versions.
For specific packages, you can always compile for source .
Look for change log on ros website for exact difference
Originally posted by prince with karma: 660 on 2014-08-31
This answer was ACCEPTED on the original site
Post score: 2
Original comments
Comment by Zero on 2017-03-27:
Hi, may I ask one question about the indigo and hydro?
so what's the difference between hydro and indigo in ssh configuration? Because when I try to use ssh to remote control the robot, I'm able to control in hydro (same program and configuration) but in Indigo I cannot make it.