If you are not a tech expert or developer then you might not be familiar with these great tools. However most of you guys have used WordPress custom fields in day-to-day wordpress life even if you dont know what custom fields in wordpress are.
How to add custom fields to wordpress
In developer words: Custom fields are beneficial fields that allow you to store extra information called meta-datausing key/value pairs.
In non-technical words: custom fields basically mean that enables you to store additional content. Either you can just keep this information to yourself and display it in back-end editor or you can display it in front-end to your visitors as per your choice.