(of two random variables)
Not independent. However, the nature of the dependence can be extremely different in different contexts, from one being completely determined by the other, to an extremely small effect. For example, if a bag has 50% red and 50% black balls in it, and event A is that the first ball drawn from the bag is red, and B is the second red, then consider the following two cases. First, if the bag has only two balls in it to start with, then if A happens B cannot, i.e. the likelihood of B is completely determined by knowledge of A. However, if the bag contains 1000 balls altogether, the conditional probability which is almost the same as P(B) when no information is available about the colour of the first ball.