Short answer
The angel of death takes your soul, your body is washed and buried, and in the grave two angels question you. You then stay in barzakh, the life of the grave, until the Day of Resurrection, when everyone is raised, judged, and sent to Jannah or Jahannam.
Sunni creed affirms the taking of the soul by the angel of death, the questioning in the grave, the reward or punishment of the grave, bodily resurrection, the reckoning, the scales, the bridge (sirat), and Jannah and Jahannam, all as true realities.
The four schools agree on this.
Explanation
Death. Every soul will taste death (3:185). The angel of death, sent by Allah, takes the soul. Hadith describe the believer's soul leaving gently and being met by angels with good news, and the disbeliever's soul being taken harshly.
The grave. After burial, the Prophet ﷺ said, the dead person even hears the footsteps of the people walking away. Two angels then sit him up and question him about his Lord, his religion and his Prophet. The grave becomes a garden for the one who answers well and a place of punishment for the one who fails. See the questions in the grave.
Barzakh. The Quran calls the time between death and resurrection a barrier (barzakh) that no one returns from (23:100). The soul is aware and feels comfort or pain, while the body returns to the earth. Our guide Barzakh and the afterlife explains this stage.
Resurrection and judgement. At the end of time the trumpet is blown and all people are raised in their bodies. Each person receives a book of deeds, deeds are weighed, and everyone crosses the sirat, a bridge over Hell. Believers enter Jannah; some sinful believers may be punished for a while first unless Allah forgives them, and those who died in disbelief remain in the Fire.
What carries you through all of it is what you live by now: faith in Allah, prayer, good deeds and repentance.
The evidence
Quran, Surah As-Sajda 32:11
۞ قُلْ يَتَوَفَّىٰكُم مَّلَكُ ٱلْمَوْتِ ٱلَّذِى وُكِّلَ بِكُمْ ثُمَّ إِلَىٰ رَبِّكُمْ تُرْجَعُونَ ﴿١١﴾
Say, "The angel of death will take you who has been entrusted with you. Then to your Lord you will be returned."
The angel of death is given charge of taking souls.
Quran, Surah Al-Muminoon 23:99-100
حَتَّىٰٓ إِذَا جَآءَ أَحَدَهُمُ ٱلْمَوْتُ قَالَ رَبِّ ٱرْجِعُونِ ﴿٩٩﴾ لَعَلِّىٓ أَعْمَلُ صَٰلِحًۭا فِيمَا تَرَكْتُ ۚ كَلَّآ ۚ إِنَّهَا كَلِمَةٌ هُوَ قَآئِلُهَا ۖ وَمِن وَرَآئِهِم بَرْزَخٌ إِلَىٰ يَوْمِ يُبْعَثُونَ ﴿١٠٠﴾
[For such is the state of the disbelievers], until, when death comes to one of them, he says, "My Lord, send me back That I might do righteousness in that which I left behind." No! It is only a word he is saying; and behind them is a barrier until the Day they are resurrected.
Names barzakh, the stage between death and resurrection.
Quran, Surah Aal-i-Imraan 3:185
كُلُّ نَفْسٍۢ ذَآئِقَةُ ٱلْمَوْتِ ۗ وَإِنَّمَا تُوَفَّوْنَ أُجُورَكُمْ يَوْمَ ٱلْقِيَٰمَةِ ۖ فَمَن زُحْزِحَ عَنِ ٱلنَّارِ وَأُدْخِلَ ٱلْجَنَّةَ فَقَدْ فَازَ ۗ وَمَا ٱلْحَيَوٰةُ ٱلدُّنْيَآ إِلَّا مَتَٰعُ ٱلْغُرُورِ ﴿١٨٥﴾
Every soul will taste death, and you will only be given your [full] compensation on the Day of Resurrection. So he who is drawn away from the Fire and admitted to Paradise has attained [his desire]. And what is the life of this world except the enjoyment of delusion.
Death comes to all, and full reward is given on the Day of Resurrection.
Sahih al-Bukhari 1338
Sahih... الْعَبْدُ إِذَا وُضِعَ فِي قَبْرِهِ وَتُوُلِّيَ وَذَهَبَ أَصْحَابُهُ ...
"When a servant is placed in his grave and his companions turn and leave, he hears the sound of their sandals, and two angels come to him."
Describes what happens straight after burial.
Where the ruling is recorded
- al-Fiqh al-Akbar (Imam Abu Hanifa), Section on the grave, resurrection and the scales. Affirms the questioning in the grave, the resurrection, the scales and the reckoning as true.
- al-Aqida al-Tahawiyya, Section on the angel of death, the grave and the resurrection. Lists the stages of the afterlife that Sunni Muslims believe in.
This answer is pending review by the scholars on our team. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.