The first difference you should know is that "потом" is only a simple adverb ("later", "then") while "позже" is a comparative that can can also tell you "later than what" the even happens. Second, "позже" implies that, probably, some time passed between the actions. Doesn't work if the actions follow one after another. Use "потом" when talking about the sequence of actions. Use "потом" or "позже" referring to "sometime later" («Потом поговорим!»="We'll talk later"). Use "позже" when you need a comparison relative to something else ("Я пришёл позже тебя", "Урок начался на пять минут позже"). Note also that at the beginning of the sentence the use of "позже" instead of "потом" in a sequence of events sounds slightly bookish ("Позже я отправился в парк"). At least, I probably woulnd't use it in my speech like that. And, of course, it means that some time passed.

К предшественникам добавить нечего. Они очень хорошо объяснили. Исправлю только сам вопрос: "Потом и позже, какие разницы у них?" Более звучно было бы "... как разница между ними?" / ... в чем разница?"/ ... объясните разницу у этих слов"

потом - then. Указывает очередность действий, то есть после чего-либо. Я приеду домой, а потом тебе позвоню. позже - later, то есть через некоторое время. Я перезвоню тебе позже. Но в разговорной речи во многих фразах большой разницы нет. Примерно так. Возможно, кто-то еще дополнит.

There's a similar word "затем". It fits to (2), and doesn't fit to (1). Compared with "потом", "затем" is more leterary/less informal and "затем" means 'immediately after'/'as the next step'. So.... Потом is something intermediate between затем and позже, and more informal than both.

позже= later. A minute later, a month later, a year, a century later - all these are 'later'. It emphasizes the time passed, not just the sequence of events. потом = 'after that', 'then'. It is more about the sequence. (1) Both are used in phrases like 'i'll write you later', though 'потом' would be more informal here. (2) Потом is normally used in "he has done this, then (потом) he did that". "позже" would give a different meaning here.