Input Field

Input fields give people a way to enter and edit text. They’re used in forms, modal dialog, tables, and other surfaces where text input is required.

Types of Text field

Use a multi-line text field when long entries are expected.
Don't place a text field in the middle of a sentence, because the sentence structure might not make sense in all languages. For example, "Remind me in [textfield] weeks" should instead read, "Remind me in this many weeks: [textfield]".
Format the text field for the expected entry. For example, when someone needs to enter a phone number, use an input mask to indicate that three sets of digits should be entered.

Include a short label above the text field to communicate what information should be entered. Don't use placeholder text instead of a label. Placeholder text poses a variety of accessibility issues (including possible problems with color/contrast, and people thinking the form input is already filled out).
When part of a form, make it clear which fields are required vs. optional. If the input is required, add an asterisk "*" to the label.
Use sentence-style capitalization (only capitalize the first word).