Answer 1
"Halal" just means "permitted" as "haram" means "forbidden." For many things and actions there are three degrees between: "encouraged," "neutral" and "discouraged."
But perhaps the question is about WHY some things should be halal and others not. This is more difficult. From a time too distant to account, certain foods have been avoided by both Jews and Arabs. Pork is the best known forbidden food, but there are others. In practice, halal is the same as kosher. In fact, before there were halal butcher shops, Muslims simply shopped kosher.
Was it a question of sanitation (pigs do carry human diseases)? Or were swine once sacred animals, too holy to be eaten, as cows are to the Hindus? Or was it just a matter of distinguishing one people from their neighbors. All these viewpoints have their advocates.
Probably the truest answer, though not the most satisfying, is, "Because it's our tradition."
Commentary on Answer 1
"Halal" and "Kosher" are not synonymous. The process of Islamic Slaughter (Dhabiha) and Jewish Slaughter (Shechita) are different in their specifics, making Halal meat not-Kosher. Additionally while Judaism prohibits shellfish and other marine invertebrates, only the Sunni Hanafi School follows these prohibitions. Additionally, Islam prohibits alcohol, which is permitted in Judaism.
The Muslims eat only Halal food.
Muslims do not eat halal for scientific reasons; they do it because God commanded that they eat this way.
Fish and all sea food types are allowed (halal) for Muslims to eat.
halal is when the muslims pray and then kill the animal to eat it.
Halal or Lawful means the foods which the Muslims are permitted to eat.
Yes, Kosher meat is halal for Muslims to eat
Muslims are not alowed to eat pork, they can eat all the other meats but they have to be halal.
yes Muslim can eat hotdogs only if they are halal. There are all kinds of hotdogs chicken, beef and pig but muslims cant eat pig.
Yes, of halal animals.
They are Muslims, so they do eat what all other Muslims eat - halal food. And no pork!
Yes, they do. It's halal (allowed by the Islamic religion)
All fish and sea food types are halal and are allowed for Muslims to eat unless any of them proved to be poisonous.