Apple cider vinegar is a vinegar made from the juice of crushed apples. It can be purchased in two forms: filtered or unfiltered.
What's the difference? Both versions are made with a "mother" (a substance composed of cellulose and friendly bacteria), which turns the apple juice from alcohol to actual vinegar. It's the mother that causes the only major difference between the two types of apple cider vinegar.
Filtered ACV will have no trace of the mother and most likely be pasteurized. Unfiltered ACV will have a small amount of the mother and most likely be organic and unpasteurized.
How does this affect the vinegar and its uses? Filtered apple cider vinegar will always appear clearer, which may be something that matters for the sake of presentation. It also usually has a milder apple flavor and is commonly the cheaper option at most grocery stores.
Unfiltered apple cider vinegar has traces of the mother which may hold health benefits and allows you to make your own vinegar with it. Some brands can also have a more prominent apple taste.
Which should you buy? Overall, which one you choose just depends on how tight your budget is and whether it being more/less processed matters to you. Either will return delicious results in recipes for salad dressings, glazes, and more!