In Islam death is seen as the separation of the soul from the body, and its transfer from this world to the afterlife it is the termination of the worldly life and the beginning of the afterlife.
Death is inevitable and guaranteed to each and every living being. It is the one thing that we can be certain about in life, we are born to die. Every soul shall have a taste of death no matter who they are, this is confirmed for us many times in the Quran:
“Every soul shall have a taste of death: and only on the Day of Judgement shall you be paid your full recompense.” (Quran 3:185)
“Every soul shall have a taste of death: and We test you by evil and by good, by way of trial. To Us must you return.” (21:35)
“Every soul shall have a taste of death: In the end to Us shall you be brought back.” (29:57)
The following videos explains nicely what is the soul and the journey of the soul.