Take care this is not simple, it's a major sin.!!!
~~ Prophet Muhammad (peace be upon him) said, "Do you know what backbiting is?" They said, "God and His Messenger know best." He then said, "It is to say something about your brother that he would dislike." Someone then asked him, "But what if what I say is true?" The Messenger of God said, "If what you say about him is true, you are backbiting him, but if it is not true then you have slandered him." (Muslim)
أتدرون ما الغيبة ؟ قالوا : الله ورسوله أعلم . قال : ذكرك أخاك بما يكره ، قيل : أفرأيت إن كان في أخي ما أقول ؟ قال : إن كان فيه ما تقول ، فقد اغتبته . وإن لم يكن فيه ، فقد بهته
صحيح مسلم
O you who have believed, avoid much [negative] assumption. Indeed, some assumption is sin. And do not spy or backbite each other. Would one of you like to eat the flesh of his brother when dead? You would detest it. And fear Allah; indeed, Allah is Accepting of repentance and Merciful. (Al-Hujurat 49:12 )
يَا أَيُّهَا الَّذِينَ آمَنُوا اجْتَنِبُوا كَثِيرًا مِّنَ الظَّنِّ إِنَّ بَعْضَ الظَّنِّ إِثْمٌ ۖ وَلَا تَجَسَّسُوا وَلَا يَغْتَب بَّعْضُكُم بَعْضًا ۚ أَيُحِبُّ أَحَدُكُمْ أَن يَأْكُلَ لَحْمَ أَخِيهِ مَيْتًا فَكَرِهْتُمُوهُ ۚ وَاتَّقُوا اللَّـهَ ۚ إِنَّ اللَّـهَ تَوَّابٌ رَّحِيمٌ
سورة الحجرات
"I asked the Messenger of God: Who is the best Muslim? The Messenger of God replied, "He is the one from whom Muslims are safe from the evil of his tongue and hands." (Muslim)
سئل رسول الله صلى الله عليه وسلم : أي المسلمين أفضل ؟
فقال: من سلم المسلمون من لسانه ويده .
صحيح مسلم