What does this string of cmd prompts mean?

Question

F:\>cd atom

F:\atom>browser-sync start --server --files "css/*.css, *.html "

'node' is not recognized as an internal or external command, operable program

or batch file.

F:\atom>browser-sync start --server --files "css/*.css, *.html"

'node' Not recognized as an internal or external command, operable program

or batch file.

F:\atom>