Matla — the opening sheʿr
The matla is the opening sheʿr of a ghazal. Both of its misras rhyme — meaning both end with the qafia (and the radif, if there is one). This is a structural commitment: the poet uses the matla to declare the rhyme scheme of the whole ghazal. Every subsequent sheʿr will rhyme its second misra against whatever the matla established.
Maqta — the closing sheʿr
The maqtais the closing sheʿr — the last one. By tradition, the maqta contains the poet's takhallus (see below). It is the poet signing their work inside the work itself, often with a wink or a rueful joke at their own expense.
Takhallus — the pen-name
The takhallusis the poet's pen-name — a single word, often resonant or symbolic, that the poet picks early in their career and uses for the rest of their life. Mirza Asadullah Khan was known as Ghalib, meaning conqueror. Allama Muhammad Iqbal used Iqbal, meaning fortune. Mir Taqi was Mir. Faiz Ahmed Khan was Faiz, meaning grace.
The takhallus appears in the maqta as a kind of grammatical third person: Ghalib, what were you thinking? The poet talks about themselves, by name, inside their own poem. The effect is intimate and ironic at the same time.