Look at this large bowl-shaped container which is very popular in Asia but not in Western countries. It can be used to contain water or you can wash your hands or face using it.
In the dictionary,
basin: a large round bowl for holding liquids or (in British English) for preparing foods in; the amount of liquid, etc. in a basin
a pudding basin
vessel (old use or specialist) a container used for holding liquids, such as a bowl, cup, etc.
a Bronze Age drinking vessel
What is it called? A basin or vessel?