What is mean 'conflict' I don't get it who is explain to me or how to solve save me


indent preformatted text by 4 spaces

$ rails generate controller Messages
conflict app/controllers/messages_controller
Overwrite /home/ccuser/workspace/learn-rails-one-
model/app/controllers/messages_controller.rb? (en
ter "h" for help) [Ynaqdh]


It appears to suggest that that file already exists, and is asking you what to do, your options are between the brackets [] and hitting enter defaults to Y for yes, which is what I'd do. typing h would likely explain more what the alternatives are