The correct spelling of the phrase is "giving back," not "giving backs." The phonetic transcription for "giving back" is /ˈɡɪv.ɪŋ bæk/. "Giving" is pronounced with a hard "g" sound followed by the short "i" vowel sound, while "back" is pronounced with the "a" vowel sound followed by a hard "k" sound. This phrase means to give or donate something to others in order to help or support them in some way. It's important to use proper spelling and pronunciation to effectively communicate with others.
The term "giving backs" does not commonly exist in the English language, so there is no widely recognized etymology for it. It is possible that it is a colloquial or regional variation on the phrase "giving back", which means returning or repaying something in gratitude or generosity. However, any specific etymology for the term "giving backs" would likely depend on context or local usage.