Prayer, or Salah, is a supremely important activity in a Muslim's daily life. Prayer is one of the Five Pillars of Islam, and is one of the fundamental beliefs and practices of all Muslims. Salah is a prayer that is performed every single day several times per day. Salah has a ritual, a procedure that must be followed. It also has a distinct preparation and must be performed at several defined times of the day.
Salah is an obligatory requirement for all Muslims; however, there are a few exception for special cases in which Salah is difficult (for example, for people that are traveling or for those people that have a handicap that prevents them from performing Salah as it is stipulated. Muslims must purify themselves before praying. To do so, a Muslim must first perform an ablution with a specific set of rules and procedures. The place where Salah will take place must also be clean and adhere to some guidelines. There are also some activities or situations that may render a Muslim impure for Salah (for example, bleeding.)
To pray, there is a repetition of several actions and prayers. Each of the sequences that is to be repeated is a raka'ah. Depending on the time of day, or the circumstances of prayer, the number of raka'ah changes. For example, community prayers on Fridays have a different number of raha'ah than the daily Morning Prayer. Salah also includes some additional prayers and actions that can be done as a way to further praise God, ask for forgiveness, or to continue praying. These are not obligatory, but are considered as something virtuous. The actions involved in Salah can be altered in cases of handicap or of special circumstances that do not allow a Muslim to perform them all. After having finished with prayer, there are usually other prayers held. Sometimes some specific Surah of the Qur'an is recited, or additional prayers are read or recited. Sometimes Salah is part of a larger ritual for a special occasion or celebration, in which case there are other activities that surround the normal prayer.
The times of prayer can differ among different sects of Islam. Most Muslims pray five times per day, according to the movement of the sun. The usual prayers are at dawn, at noon, a few hours after noon, before sunset, and at night. Some of these prayers can be combined depending on the circumstances; for example, Shia Muslims usually perform these prayers in sets of two, usually combining the noon and afternoon prayers, or the sunset and nightfall prayers. If a Muslims misses a prayer, he must make it up as soon as possible.
-- Al Arabiya Digital