"Liquid water" refers to the form of water that is common on Earth, which can be seen and felt as a wet substance. It is the type of water that flows like in rivers, fills up oceans, or appears as rain. Full definition
But new data suggest that there are zones of liquid water hundreds of meters below the surface. (sciencemag.org)
10 of these new candidates are near - Earth - size, where they have a chance of being rocky with liquid water on their surface. (pbs.org)
That's the region surrounding any star where it's not too hot and not too cold for liquid water to exist on a planetary body. (science.howstuffworks.com)