Halal means “allowed,” “lawful,” and/or “permissible.” It comes from a verb meaning, “untie, unbind, unfasten, unravel, solve, decipher.”
The milk of a cow is an example of a halal food.
Haram means “prohibited,” “unlawful,” and/or “sacred.” It comes from a verb meaning “to be forbidden, to be unlawful.”
Note that the meaning of haram depends greatly on context. When Muslims refer to Masjid al-Haram or the Haram Shareef, they are using the word in the sense of being sacred, referring to the masjid surrounding the Ka’aba in Mecca.
Bacon, meat from the side, back, or belly of a pig, is an example of a haram food. There is a clear daleel (piece of evidence) supporting the claim that pork is haram is Islam. Quran 2:173 says, “He [Allah] has only prohibited to you dead meat, and blood, and the flesh of swine and that on which any name hath been invoked besides that of God.” (Hussaini and Sakr, 17, following Yusuf Ali). “Swine” refers exclusively to the animal known in contemporary English as the pig.
When Muslims refer to pork as haram (pronounced with a longer second vowel than above), they mean that pork is prohibited. They do NOT mean that pork is sacred to Muslims.
Mohammad M. Hussaini and Dr. Ahmad H. Sakr, Islamic Dietary Laws and Practices, Chicago: IFANCA, 1983,9.
R. Harmsen, “Halal and Haram.” http://rudhar.com/etymolog/halal.htm, 2011