Difference between Rubai, Ghazal, Nazm, Qawwali and Shayari
I cannot explain these poetical forms without, talking about a bit of the history of the Indian Subcontinent. The Ghazals, Rubais, and Nazm had their origins in Persian (erstwhile Iran-Iraq). With the invasion of the Indian Sub-continent by the Mughal Emperors, the poetical forms from Persia, reached Indian shores. By 1700s several poets of Indian Birth had started writing in rubais, and Ghazals. Indian Ghazals were heavily influenced by an Islamic religious offshoot called “Sufism”. Sufism unlike their Arabic counterparts gave emphasis on singing and dancing. For them God was an experience, not a set of rules to be followed.
Over a period of a century, Indian and Pakistani Ghazals, attained a distinct characteristics.
RUBAI (plural Rubaiyat)
After the 11 century, The Persians refined their Rubais and developed it separately from their counterparts found in the Indian sub-continent. The Persian Rubais were quatrains. The most popular of them in the western world is the “Rubaiyat of Omar Khayyam”.
It's hard for me to understand a Rubai, since it uses lots of Persian words.
The poems written in the Indian-subcontinent were of two basic genres: Nazm and Ghazal.
Nazm is more like a storytelling. It has only one subject matter. it is less restrictive than Ghazal can contain philosophical, romance, love shayari and similar themes.