All the people have the custom of greeting one another, and every group has its own distinctive greeting that distinguishes them from other people. And in Islam the greeting is ‘Assalaamu Alaikum’. The meaning of this phrase is ‘May peace be upon you’.
This is the standard Islamic greeting around the world. The reference to greeting with Salaam (peace) is even found in the Qu’ran. Although this is an Islamic greeting, it is often seen that people who live in Islamic countries whether they are Muslims or not use this greeting freely.
Islam is a religion of peace and rightly so the Islamic greeting is of wishing one another peace. In Islam greeting one another with Salaam is highly recommended whether you know them or not. Wishing each other with the term ‘Assalaamu Alaikum’ perhaps has more significance now than ever before as it is peace that is missing from our lives the most in this present modern world. Today, we have prosperity which could bring us peace but sadly there is no welfare for all.
There are several etiquette of the Islamic greeting and the most important is that if one greets you with a greeting then he must reply to that greeting with a better greeting or at least return the greeting. So when one is greeted with ‘Assalaamu Alaikum’, the most common reply is ‘Wa Alaikum Assalaam.’ Which means ‘And upon you be peace.’ But it is recommended that he replies with the full version of the Islamic greeting. ‘Assalaamu Alaikum Wa Rahmatullahi Wa Barakatuh’ which means "Peace be unto you and so may the mercy of Allah and His blessings".
When one greets with the full Islamic greeting with a sincere heart it is nothing less than a prayer for the other and when that is replied in the same token good will and love breeds in society.
Once Prophet Mohammad was asked “What is the best thing in Islam?” He said, “Feeding others and giving the greeting of salaam to those whom you know and those whom you do not know.”