Muslims believe that there will be a physical resurrection on the Day of Judgement (Yawm al-Din), so they disapprove of cremation, and always use burial. Allah will put people’s bodies back together again:
Does man imagine that We shall not assemble his bones? Indeed, We have the power to restore his very finger tips.Qur'an 75:3-4
In the name of Allah, Most Gracious, Ever Merciful. All types of perfect praise belong to Allah alone, the Lord of all the worlds, Most Gracious, Ever Merciful, Master of the Day of Judgement. Thee alone do we worship and Thee alone do we implore for help. Guide us along the straight path - the path of those on whom Thou hast bestowed Thy favours, those who have not incurred Thy displeasure, and those who have not gone astray.Qur'an 1:1-7
This quotation reflects beliefs about the afterlife and the Day of Judgement which awaits all Muslims.
Then, once the body is in the ground, people say:
From the earth have We created you, and into it We shall cause you to return and from it shall We bring you forth once more.Qur'an 20:55
Graves are raised above ground level so that the place of burial is clearly marked, and so that people do not walk on them by accident. Large and elaborate gravestones are not usually found, but they are not forbidden.