It's a bit more specific than just saying "time" in English. It usually refers to a short period of time or a moment.
Here are some examples:
* "Estoy aquí por un rato." (I am here for a while.)
* "Esperaré un rato." (I will wait a while.)
* "Pasé un rato agradable con mis amigos." (I had a nice time with my friends.)
It's important to note that "el rato" is masculine, so you'll need to use the masculine definite article "el" before it.