What is use of feather in Photoshop?

You select something, then run the feathering on the selection. Little more detail: You want to frame a picture of an attractive female (mother, wife, girlfriend, daughter, cat...) in a soft-edged heart surrounded by a red background. 1. Open picture of female. Set the background color to red. 2. Use pen tool to draw heart well inside the boundary of the photo. 3. Make the heart into a selection. Run the Feather command--the bigger the number, the more gentle will be the feathering. 4. Invert the selection (this will select everything outside the heart) and delete to complete the job.