Every Namaz is made up of different sections called rakats.

There 5 namaz'es

Salat al-fajr: dawn, before sunrise
Salat al-zuhr: midday, after the sun passes its highest
Salat al-'asr: the late part of the afternoon
Salat al-maghrib: just after sunset
Salat al-'isha: between sunset and midnight

Rakats

Farz must be read
Sunnah is optional but you get rewards in the hereafter if you red it as the Prophet SAW read it.