They basically mean the same but there might be some differences in the contexts where they are typically used. If I would have to explain who to make a difference between those two, well, to me "custom" is more like a habit, something you don't really think about you just do it. "Tradition", on the other hand, is something with a deeper meaning, possibly religious, cultural or family-specific that guides the person's/groups way of behaviour or performance in certain situations. But these are just my opinions. According to CambridgeDictionaries Online: Custom = a way of behaving or a belief which has been established for a long time; a local/ancient custom Tradition = a belief, principle or way of acting which people in a particular society or group have continued to follow for a long time

custom and Tradition- Actions and belief systems that are a cultural norm. (this may be a culture inside of a society or the whole society) They are seen as a proper habitual choices. These range greatly with countless topics. (for instance what to ware, what not to ware - how and when to talk to God(s), how not to - what and when to eat, what not to eat - how to interact with people, who to interact with, and so on.) The difference between them is this: A custom is not always thought about as a special thing to the culture while the individual is doing it (even though it is special and unique to the culture.) It is being done (possibly) without reverence and out of habit.) It might not even be thought of until someone goes against (or does not follow) the custom. A Tradition is thought of as special and unique to the culture. It is thought of as such while it is being performed. It may be a habit, yet it is not thought of as a habit; it is thought of in a more reverent way than that.

A tradition is a practice that started many generations earlier. It can include holiday celebrations, weddings, methods of selecting a spouse and funeral grieving. Tradition probably came from your nationality heritage, and how it was done in "the old country". All these situations can include customs as well. However, customs today may have changed from the traditional system. If you say, "our family customarily opens our Christmas presents on Christmas Eve, and we eat Christmas dinner with my wife's family", that is your custom or practice every year. But you could say, it is a tradition in America to put up a Christmas tree and under the tree we have wrapped presents. The Jewish tradition of grieving for the dead includes 5 stages. The jewish customs in a funeral does not include the display of flowers. The words can be interchangeable for all practical purposes.