Salaat is the arabic name for the obligatory prayers which are performed five times a day.
The five-time prayers become obligatory from the moment a person embraces Islam. This is an extremely important tenet of Islam and has been enjoined with great emphasis in the Holy Quran. It is a form of worship which establishes the link between man and his Creator and Benefactor, Allah. Through Salaat a person communes with his Lord, the Creator and the Sustainer of the Universe.
Just as performing Salaat is obligatory, learning to perform it in the prescribed way is also obligatory - and one should know what he/she is saying to his/her Lord.
The five prayers are as follows with rough time of day they are performedat earliest and latest.
Starts at dawn or morning twilight Ends just before sunrise
Starts at approximately 5 minutes after Zawaal Ends at start of Asar time
The start of Asar is dependant upon the length of the shadow that is cast by an object.
Different schools use different criteria. Ends just before sunset
Starts at sunset Ends at the start of Isha (i.e. when there is reddishness in the sky)
Starts after dusk Ends when the evening twilight disappears (i.e. when it first starts to get light