Here are some examples:
* "I saw something strange in the garden." (The speaker doesn't specify what they saw)
* "There's something wrong with the car." (The speaker doesn't specify what's wrong)
* "Do you want something to drink?" (The speaker doesn't specify what kind of drink)
Other words can be used in a similar way, such as anything, someone, anyone, and somewhere. However, something is the most general term for a non-specific entity.