This short riddle asks: What has a beginning, an end, but no middle? It is one of those riddles that can have more than one accepted interpretation depending on the version.
A common answer is: a road.
A road can have a clear beginning and a clear end, while there is no single fixed place officially called “the middle.” You can certainly measure a midpoint, but the riddle is playing with the idea that only the start and finish are specifically defined.
Some versions of this riddle use answers such as a line or even a letter, so the wording is intentionally loose. The classic intended idea is something that clearly starts and finishes without having one named middle point.
If you thought of another answer that fits, it may also work.
