In buddhism there is the four noble truths, a teaching about living life and facing death.
In short, what many people afraid in death (or in life generally) is the fear of losing, either losing their possession, losing their loved ones or how those loved ones will feel when losing you, losing your ability to do your job, etc.
In the teaching, if someone is able to overcome that fear (suffering / dissatisfaction), he / she can accept death as a cycle of living and live more relaxed life.
In short, what many people afraid in death (or in life generally) is the fear of losing, either losing their possession, losing their loved ones or how those loved ones will feel when losing you, losing your ability to do your job, etc.
In the teaching, if someone is able to overcome that fear (suffering / dissatisfaction), he / she can accept death as a cycle of living and live more relaxed life.