I thought that epoch and timestamp represented the same value, with the same number, although getting values with getTime() of class Timestamp in Java, this does not it's like that.
The epoch value seems to be the one obtained by the method mentioned between / 1000, that is epoch time is measured in seconds and the timestamp in milliseconds . I have consulted several pages and it does not clarify the difference. It seems that timestamp, indicates a certain moment, but it has different implementations according to the language, and for example, in mysql it is not even represented as a number.