Selenium gives you the facility to check the visibility of a webElement. The webelement can be buttons, drop down boxes, checkbox etc.
The 3 methods used for this are as follows:
isDisplayed() is used to verify that the element is present or not. The method returns true if the element is present.
isSelected() is used to verify whether the element is selected or not.
isEnabled() is used to verify whether the element is enabled or not.