When there is a repetitive appearance of certain expressions in a field, you can prefer a single select field rather than manually entering the terms repeatedly. You can choose only one option from a drop-down menu with multiple predefined choices.

How does it work? 

1. Choose Single Select from the list of fields available.
2. This opens up a dialog box. Click the + ADD AN OPTION button to add the list of options/choices.
3. Using the delete icon, you can delete the options that are not required.
4. Sort (A-Z) / (Z-A) option to arrange the options at your convenience to pick one easily when you fill in the records.
5. Coloured Option, is to differentiate between the choices quickly. By default, choices are color-coded, but you can customize them.
6. Using the drag & drop option, You can swap the choices between each other.
7. Hit Enter.