Infinity is a big idea that, for most of us, is impossible to fully grasp. Even so, there are at least two symbols, both mathematical, that convey its meaning perfectly and in surprisingly simple ways.
The first one is called a "lemniscate" and most of us are familiar with it as the figure-8 symbol. It's made up of one continuous line that has no beginning or end, such that if you traced its path with your finger, it would go on forever and ever.
The second one is called a "Mobius strip" and often appears as a circle with one twisted edge. It is this simple twist that turns the circle into just one surface that you can run your finger along forever.
The lemniscate and Mobius strip are so pure and simple that they have transcended mathematics to become symbols that are both elegant and poetic. Both are often given as gifts to loved ones as symbols of eternal love or friendship.