When reading input from an Android user with an EditText, you have a simple way to help that user out by setting the InputType. If you need the user to input a number, for example, you set the number InputType, and the user will automatically key a numeric keypad instead of the full QWERTY. This saves the user a little bit of time and mental energy, and helps avoid mistakes with input.
Beyond just text and numbers, though, are a range of options that produce very subtle changes in the keyboard that Android brings up. Below I explore which options bring up which keypad by default.
First, the standard keyboard, which covers a lot of the input types.
For our first subtle variation, the URI keyboard replaces the comma with a slash.
The short message keyboard replaces the enter key with emoji access.
The number password variant reduces the available symbols and focuses just on the numbers.
The phone class adds some symbols common for phone number formatting, plus star & hash.
The date/time class gives you a slash and colon for formatting.
The date variant only allows for a slash.
The time variant only allows a colon.