Apple cider vinegar is used both as a condiment, and as a home remedy. It has a lot of potential health benefits and a lot of uses for treating damaged hair, skin conditions, and general ailments.
Why is Apple Cider Vinegar So Useful?
Apple cider vinegar is rich in enzymes and amino acids, and also contains a number of vitamins and minerals. It has a long history of being used as a home remedy, and legends state that as early as 5000 B.C it was used as a preservative and that by 420BC it was used to treat wounds, as Hippocrates had found that it had antibacterial properties, although his explanation may not have been as scientific as that. More recently, it has been found to have an anti-glycaemic effect, making it useful for managing blood sugar. 
Apple cider vinegar is promoted as something that can have a useful impact on weight loss, can control blood sugar, and potentially have other beneficial effects. There is some truth to those claims, but those who promote apple cider vinegar as being a potential cure for diabetes are over-stating the benefits.  It is indeed healthful, and it can help to regulate blood sugar to a degree, which can help with overall health and energy levels, but it is not a miracle cure.
Apple cider vinegar is anti-microbial, and it can be useful for keeping foods fresh. 
Potentially, it could even be useful for cleansing your skin, or for use as a toner, because of the pH of the solution. It could also be a good cleanser and conditioner for your hair, although you would need to dilute it heavily to stop damage.
Apple Cider Versus Other Vinegars
There have been several studies conducted which monitored the use of apple cider vinegar versus malt vinegar and a placebo for various health-promoting effects. Those studies have found that apple cider vinegar, when used sparingly in a diet, could have a positive impact on certain health markers such as cholesterol levels. The key here is that it should be used sparingly. If someone drinks lots of vinegar, then that could do damage to their oesophagus. .
In moderation, it can be useful for lowering cholesterol. There are some who believe that it may have an anti-inflammatory effect which can be good for the skin as well, although this is more questionable.
Using Apple Cider Vinegar
If you want to use apple cider vinegar as a cleanser, toner, or hair wash then dilute it heavily first. Using it as a part of a facial rinse, perhaps with essential oils, could help to reduce the presence of unwanted bacteria and promote a healthy and youthful complexion. It may also nourish your hair and help to ward off split ends.
If you are going to use it orally, then again, use it sparingly as a part of a salad dressing or other condiment. This will give the benefits of the nutrients without the damage from the acetic acid. Note that both malt vinegar and apple cider vinegar have similar concentrations of acetic acid. This acid is useful for breaking down starches and can help with preventing the sugar spike which is such a problem when people eat carb-heavy meals.
You will still need to eat a healthy diet and to generally look after yourself. The ‘home remedies’ of drinking apple cider vinegar on a morning to promote weight loss are overblown and won’t really have much of an impact. As a part of a healthy lifestyle, though, it can be a valuable addition.