can someone explain time dilation?

Time dilation is a myth. Time is a man made thing. Time can only be described as now. Now has no dimension, all events take place on the cusp on now. When an event ends if becomes the past and can only be recalled as an image or record, the next event begins the unfolding of the future.

Time dilates as a moving object approaches the speed of light, relative to a stationary observer. A similar effect can happen when an object finds itself in a strong gravitational field, such as by approaching a black hole. This is because we live in a universe where space and time are are not seperate, but are inter-connected to form "space-time". For more detail read about the general theory of relativity.

BTW the contributor who said that time dilation does not exist is way off the mark. Its existence has been proven by many experiments: one famous one being when atomic clocks circumnavigating the world in an aeroplane were seen to run more slowly than their stationary counterparts.

there is no such thing it is the product of complex mathematical games which have no meaning or relevance to the real world