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.
METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.