Still Learning OSX from a PC Question

[iRobby]

I have a question about the top left buttons on the windows:


please explain to me the function of the Green Yellow and Red buttons

My understanding:

Red: Closes the application
Yellow: Minimizes and keeps applications open
Green: have no idea!

 

[simsaladimbamba]

RED: Closes the window, not the application, unless the application only has one window (compare System Preferences with Preview).

GREEN: sizes the window up/down according to displayed content, can be used to maximise a window, if needed.

To learn more about Mac OS X: Helpful Information for Any Mac User by GGJstudios​

 

[Krazy Bill]

Coming from Windows, you're going to have a hard time wrapping your head around those 3 little lights.

First get used to Applications that stay running with no windows. And yes, it's quite common to have an inactive window from another application show directly under the menu bar of an application you thought you closed.

I installed a 3rd party app called RightZoom. It forces the window to consume the entire display when pressing the Green "optimize" button (instead of merely resizing the window to fit the text).