When adding a Custom Field, the first option you need to choose is the types of fields. Types of fields will determine what kind of field are you creating.
Multi Selection
Multi selection is where you can select multiple choices as an answer. [Refer the picture above for an example]
Date
Date is where you can select a date from the calendar provided as an answer, [Refer the picture above for an example]
Single Selection
Single selection is where you can make 1 choice from the selection as an answer. [Refer the picture above for an example]
List Selection
List selection is where you can make 1 choice from the drop-down list provided as an answer. [Refer the picture above for an example]
Text
Text is where you can enter text sentences in the space provided as a form of answer. [Refer the picture above for an example]