# Fields

In the last section, we learned about the parts of a template and how they can include references to your data using curly brackets, like `{first_name}`.  Now we're going to learn how to create those references with "fields."

## What is a Field?

A field is how you define a type of data that you want to store and use in Entry Point AI. Fields can be used in multiple places, including [templates](https://docs.entrypointai.com/key-concepts/templates) and [transforms](https://docs.entrypointai.com/key-concepts/transforms).

If you have a spreadsheet of data, the field name is equivalent to your column header. Fields also consist of a reference and a *type*.

There are four types of Fields in Entry Point:

* Text (default)
* URL
* Predefined Option: a list of possible values (like a dropdown)
* Number

### Field References and Values

The field reference is a lowercase word or series of words, separated by underscores instead of spaces (camel case). It's how to refer to your field in a [template](https://docs.entrypointai.com/key-concepts/templates), like a variable.

Examples of field references:

* `input`
* `output`
* `user_inquiry`
* `first_name`
* `list_of_recommendations`

When you use a reference in a template, the actual *values* for a field are get inserted to replace the field *reference* for prompts and training. It's like a placeholder.

For example, if you reference a field using `{first_name`}, then the value might be Bob or Linda. Any field you create will end up having many different possible values.

Going back to our spreadsheet analogy, the field *value* is what we'd see for each cell in a column.