Al dente, in its most literal translation, is an Italian term meaning: "to the tooth" [al = to the, dente = tooth/teeth]. The history of the term came from the process whereby the cook would test the consistency/texture of the food with their teeth. If it was right to the bite then it was "al dente". It's the point at which your food, like pasta, is not mushy and not hard either. It's just right.
Although al dente is most commonly thought of as being a pasta term it actually spans the gamut of many foods:
Rice and Beans
When rice and/or beans are al dente they have a resilience to them that they don't lose their form and not because they are still undercooked. They've gotten to the peak of their perfection.
When vegetables are al dente they are a "tender" crisp. They're not water logged, devoid of their vibrant color or crisp flavor, their cellular structure has not broken down to the point where they lose their character and turn to a stewey mess. They have a bend to them, are flexible, yet not limp. You are cooking the vegetables just to the point to get rid of the raw flavor, to infuse them with or bring out their flavor and that's it.
When you see the term used on meats it's almost the equivalent to parboiling in order to finish off the cooking later, like if you're going to glaze or sugar cook your meats, you wouldn't want to sugar your food during the initial phase of your process, because you would risk over cooking the sugar on the meat and either burning or causing it to harden. To troubleshoot that you would cook your meat, be it pork, poultry, etc. to the "al dente" stage or the "under cooked" or "just under done" first and then you would add your sugars, syrups, sweet sprinkles or whatever you're using to create that sweet and savory dance on the taste buds, and finish it off in the oven or broiler. This process keeps your flavors clean and keeps them from crystallizing taking away from your overall presentation and flavor. [This is done with "sugared bacon" allowing it to firm up while at the same time the sugars don't harden and turn into candy.]
Whether you're dealing with the traditional pasta, rice and beans, vegetables, meats etc. al dente can and should be seen as somewhat of a universal culinary term, with slight variations to it, depending on its application. Al dente for: pasta, rice and beans = firm not raw, crunchy, chalky or mushy, just firm to the bite with a little chew; vegetables - crunchy, a little flexible, but with the rawness removed; meats = just under cooked, parboiled awaiting the finishing cooking processes to complete the dish, along with or as well as, once the dish is finished, having the right textural elements to deliver the desired bite balanced with doneness and tenderness. [This is where it becomes very subjective and you will have to defer to what your clients interpretation of al dente is for them. After all... they're the ones paying you for it.]
As always, it's been been my pleasure sharing this information with you. Until next time...