Selenium identifies the elements in the application to be worked on using the 8 locators.
Those are Id, Name, ClassName, TagName, LinkText, Partial LinkText, Css Selector & xPath.
Id is unique for each and every element so it is common way to locate elements using ID Locator.
Id locators are the fastest and safest locators out of all locators.
In the above example we have identified ‘Username’ editbox using id locator