A website is a presence on the World Wide Web. As of 2017, there are more than one billion. To qualify as a bona fide site, it must be available over the Internet around the clock.
Tube means a hollow cylinder. An example of a tube is manicotti pasta. The definition of a tube is a pliable container with a screw cap at one end to keep it closed. An example of tube is the container that toothpaste comes in.
Tubers are various types of modified plant structures that are enlarged to store nutrients. They are used by plants to survive the winter or dry months, to provide energy and nutrients for regrowth during the next growing season, and as a means of asexual reproduction.