Kaplan-Meier estimation is a statistical method used to estimate the survival function from lifetime data. It helps researchers understand the time until an event occurs, such as death or failure, by creating a stepwise curve that represents the probability of survival over time. This method is particularly useful in medical research, where it can analyze patient survival rates after treatment. The Kaplan-Meier curve visually displays the proportion of patients surviving at different time points, allowing for comparisons between different groups or treatments while accounting for censored data, where some subjects may not have experienced the event by the study's end.