The point is that allele frequency remains the same. What does remains the same look like? Imagine a bag of marbles;70 are blue and 30 are white. The marbles represent genes in a population. Genetic equilibrium is a state is which the frequency of white marbles remains the same over time. There might mixing of the bag, marbles may be taken out and some added back. But after all this motion, the 70/30 ratio will remain the same.

The linked page has some clear definitions of the basic concepts.