Accessibility on web means the websites containing web pages that everyone can use. WordPress also keeps Accessibility commitment so that anyone can easily get access to pages. This is not just for impaired and handicapped users but this is also for handicapped devices.
Suppose you are accessing your website from a smartphone device or may be you are using any old Internet browser or if you are located on a place with very slow Internet connection or whatever.
WordPress widgets page also provides you accessibility option. You can easily turn it ON/OFF in situations where you cannot move your widgets with drag and drop feature.
Turning on ‘Accessibility Mode‘ through WordPress ‘Screen Options‘ option present in top right corner of your WordPress admin screen will make things much easier for you.
Widgets page with Enabled Accessibility Mode displays all widgets with an ‘Add‘ button. Clicking the ‘Add‘ button on a widget opens up a new page where you can use dropdown menu for choosing a widget area (for that specific widget). Another drop down menu lets you select the widget position.