What is the difference between rake assets:precompile and assets:precompile:all?

Question

What's the difference between these 2 tasks?

Answer 1

# from assets.rake
desc "Compile all the assets named in config.assets.precompile"
task :precompile do
  invoke_or_reboot_rake_task "assets:precompile:all"
end

Looks like you can omit the :all.