The abbreviation "etc." is Latin for “et cetera,” which is where we get “and so on” from. It’s used to indicate a list of items is continuing on. For example:
“Their new refrigerator was stocked with milk, eggs, butter, etc.”
It sort of says, “You get the idea.” While there’s nothing wrong with that, it’s best to reserve "etc." for informal writing. “You know what I mean” isn’t the kind of tone you want to take in academic writing; it has a shade of informality to it.
Furthermore, "etc." can only be used if it’s easy to discern the remaining items. For example, it’s okay to say, “She packed her lipstick, eyeshadow, blush, concealer, etc.” It’s clear we’re talking about makeup.
But, let’s take a look at a list that’s slightly less specific. “On her trip to Ireland, she packed her passport, favorite books, clothes, laptop, etc.” That’s a pretty varied list. If you were just listing official documents, books, articles of clothing, or electronics, then "etc." would be acceptable.
Although it’s likely "etc." will fall at the end of a sentence, in case it doesn’t, remember "etc." always requires a period at the end.