Halal simply means permitted or lawful, it means any food or any human consumables that are allowed to be eaten or consume in any means according to Islamic Shariah law which are elaborated by different verdicts in different occasions.
The verdicts which are very important to a Muslim to follow in daily life are elaborated in 1) Halal, 2) Haram, 3) Mushbooh and 4) Makruh or Makraha 5) Mubah.
Halal (حلال): Halal is a Quranic term which means allowed or lawful. It also means that what you are allowed to eat for e.g. goat, fish and vegetable. Halal foods and drinks are permitted for consumption by Allah-the Supreme Law Giver. Eating Halal is obligatory on every Muslim.
Haram (حرام) :Haram is a Quranic term which means prohibited or forbidden or unlawful. Whatever Allah has said you are not allowed is Haram. For e.g. stealing, alcohols, gambling, interest, betraying Islam. Haram in Islam like pork, animal slaughter other than in the name of Allah, drinking of alcohol are absolutely prohibited by Allah. Eating Haram is forbidden for every Muslim.
Mushbooh (مشبوه): Mushbooh is an Arabic term which means suspected. If one does not know the Halal or Harm status of a particular food or drink, such a food or drink is doubtful. A practicing Muslims prevents himself from consuming doubtful things.
Makrooh or Makraha(مكروه) : Makruh is an Arabic word meaning not desirable. From an Islamic point of view Makrooh is something that is disliked by Allah and so we shouldn’t do it. There are two categories of Makrooh, there are Makrooh-e-Tahrime and Makrooh-e-Tanjil. Muslims are encouraged to avoid such actions or foods as possible.
Mubah (مباح): Mubah is an Arabic term which is used to refer to an action which is considered to be neither forbidden nor recommended, and thus considered neutral religiously. This is one of the degrees of approvals Ahkam (أحكام) in Islamic Shar’iah law. The Permissible (mubah) entails neither reward nor punishment. Such acts are rewarded, however, if accompanied by a good intention.