# Concepts & Terminology

Here are some useful concepts and terms to understand if you want to access the full range of capabilities in SA5 Data. 

## Data Sources 

### Simple v. Complex Data Sources

* A **Simple Data Source** returns a single value. 
* A **Complex Data Source** returns a structure. 
  * e.g. a JSON-LD source 
  * e.g. a Collection List source 

### Implicit v. Explicit Data Sources 

* An **Implicit Data Source** is one which is available automatically with no special definition or setup.
  * e.g. query string, URL parts, and cookies are all implicit data sources in SA5 
* An **Explicit Data Source** requires special setup before it can be accessed 

## Data Binding 

### Simple v. Complex Data Binding 

1. **Simple Data Binding ( 1:1 ).** Refers to simple situations in which a *single data item* is bound to a *single, simple element* such as a text element, a checkbox, or a form input element.  These are all characterized by 1:1 bindings. 
2. **Complex Data Binding ( n:1, 1:n, n:n ).** Refers to complex binding situations that involve *Collection List data sources*, bound to *complex elements* ( tabs, sliders, select options ) or *elements groups*.  

## Data Paths  

[Data Paths](#data-paths) describe specifically what you are binding to the data bound element. 

As an example, let's say that we want to do the following; 

> I want to initialize a form input field with the `name` value from the URL query string. 

{% hint style="success" %}
Since the [query string](https://attr.sygnal.com/sa5-data/data-sources/url-query-params) is a Simple Data Source in SA5, there is no special setup required. 
{% endhint %}

To achieve this, we can simply add the following custom attribute on the Form Input element;

```
wfu-bind = $query.name
```

Here `$query.name`is the Data Path. It identifies the data we are binding. 

There are two parts, which are separated by the period (`.`) delimiter;

* `$query` is the Data Source Type 
* `name` is the Data Source Name 

### Abbreviated Data Paths 

Many commonly-used Data Source Types can be *abbreviated*.  In this example, the Query String Data Source Type can be replaced with a question mark `?`. 

This allows the attribute to be written even more efficiently as- 

```
wfu-bind = ?name
```

## Using Data Paths w/ Complex Data Sources 

SA5 data paths are designed for much more complex uses as well, such as navigating tabular and hierarchical data structures. 

{% hint style="warning" %}
This will be covered in special courses but you can find some introduction in the [Data Paths](https://attr.sygnal.com/sa5-data/concepts/data-paths) documentation. 
{% endhint %}

use a simple, implicit data source such as a