Oral sex is when you use your mouth and tongue to stimulate your partner. It is a part of normal sex. Normal sex is everything you do intimately with your partner.

Oral sex is when one person is using their mouth to stimulate the other person's genitals, and "regular" sex is when the male partner's penis goes into the other partner's vagina or anus.

Oral sex is using the mouth or tongue to stimulate the genital region of one’s partner. Regular sex is insertion of the penis into the vagina. Oral sex could result in climax or it could simply be an act of foreplay prior to the insertion of the penis, the term your question uses for “regular” sex.

Both of these acts give pleasure to the partner. The use of the term “regular” in the question seems to imply that oral sex is not regular. While some religious teachings state that this is abnormal, and perhaps even illicit, no one can tell another person what is illicit when it comes to legal interactions between consenting adults.

Some would also add that regular sex is insertion into the anus. This act is also called sodomy and is officially illegal in many states. This is a throwback law that attempts to criminalize homosexual behavior. This act, like oral sex, is completely up to the consenting adults involved. But since it is an act that is punishable, you should give it the proper consideration it deserves. A woman in my state lost her considerably lucrative and highly important position for “violating” this law.

Well, not much. They are both intimate acts. One has no risk of impregnating a woman.

There is debate as to rather oral sex is as intimate as sex (as in, if it is cheating) I say "YES!" I even think that if you engage in oral sex, you are not a virgin, even in the case of a woman, where the hymen breaking would be the sign of losing virginity