It means "I follow" or "I continue".
Here are some examples:
* "Sigo trabajando." (I continue working.)
* "Sigo tu consejo." (I follow your advice.)
* "Sigo la carretera." (I follow the road.)
It can also be used in a more figurative sense, like:
* "Sigo pensando en ti." (I keep thinking about you.)
The meaning of "sigo" can vary depending on the context. However, it always conveys the idea of continuing an action or following something.