The word "or" has a number of different meanings. This may be surprising but in fact, this conjunction is rather complex. A number of examples can be used to illustrate.
Consider the question "Do you want rice or pasta?" One meaning is that of the alternative type question. The listener is given two choices, either rice or pasta. With the alternative type question, the noun before "or" has rising intonation and the noun following "or" has falling intonation. With this type of question comes an assumption. The assumption is that the listener wants one of the two choices. However, this assumption may be incorrect. It could be that the listener wants a different choice or that the listener does not want anything. In any case, the alternative type question offers the listener two or more alternatives.
In certain cases, though, the question "Do you want rice or pasta?" may be what is called a yes-no question. Perhaps the speaker is not sure what the cafeteria is serving that day and merely wishes to ask the listener whether he/she would like whichever dish is available. With the yes-no question, the noun preceding "or" and the noun following both have falling intonation. In reality, though, the alternative type question is far more common than the yes-no.
If a parent says to his/her child, "Finish your vegetables or you won't get dessert", no alternative is offered. The parent is not asking the child to choose between two scenarios. Rather, the parent explains that if a condition is not satisfied, finishing the vegetables on the child's plate, the result will be no dessert for the child. It is in fact a warning. The child knows the outcome of not finishing his/her vegetables.
In the sentence "I don't like fishing or hunting", the speaker expresses his/her dislike of both activities. This is the equivalent of saying "I don't like fishing and I don't like hunting." The conjunction "and" would only be used here if it referred to a singular activity or unit, i.e., "I don't like fish and chips."
The conjunction "or"can also be used to signify an equivalent meaning. This is illustrated by the following: "The word "glad" means happy or joyful. In this case, two words are given as equivalents of the word "glad".
Sometimes "or" represents an approximation. In the sentence "It takes five or six days", the speaker gives an approximate number. It is possible that the activity takes more than five days and less than six. In other words, it may take any length of time between five and six such as five and a half.
The meanings of the conjunction "or" vary from one sentence to another. Though many people probably associate this conjunction with the alternative type meaning, it actually has a wide range of meanings. Among these are equivalent meanings, approximations and consequences of a condition which is not fulfilled.