Definitions of Mushayira
Mushayira: is a symposium or gathering of poets where they are invited to recite their poems.
Sher OR Shayari: is a couplet, a poem of two lines embodying a single thought and is complete in itself. A sher is also called a 'bait'.
Ashaar: The plural of Sher.
Ghazal: is a collection of mulitiple Ashaar, each conveying a complete thought without any reference to other shayari of the same ghazal. In fact, though belonging to the same ghazal, the different Ashaar therein can have completely different meaning and tone relative to one another. When read seperately, they sound independent.
Misra: A line of a couplet. In a sher, the first line is called 'misra-e-oolaa' and the second line is called 'misra-e-saanii'.