# Analytes
An analyte in EnviroData is more than just a name. 

Depending on the context, defining a single analyte can may require specifying
a combination of the following unique properties:
* name (as it is stored in envirodata database)
* analysis method
* submatrix (e.g., dissolved or solid)
* unit 
* unit group
* dislay name (as it is shown on the EnviroData UI)
* list of analyte aliases, each with their own attributes

The amount of information that EnviroData needs when determining an analyte
depends on the action being performed. For example, when ingesting a datapoint
from an EDD, EnviroData either assigns an existing analyte or creates a new one
based upon the values of the datapoint's analyte name, submatrix, and unit. The
flowchart below gives an example of this:

![analyte_flowchart](../_static/explanations/analytes/analyte_flow_chart.png)

As a concrete example, imagine the following analyte exists in your EnviroData
database:

* name: Aluminum (Al)
* Submatrix: Dissolved
* Method: EPA 6020B R2 m
* Default Units: mg/L
* Unit Group: Concentration (liquid)

Where the Concentration (liquid) Unit group contains the following units:

* mg/L
* ug/L
* ng/L
* g/L

Now imagine 4 datapoints of an EDD are ingested, displayed in the image below. How many new analytes will be created?

![EDD_example](../_static/explanations/analytes/edd_example.PNG)

The first two rows will be recognized as existing analytes, since both of their
supplied units exist within the Concentration (liquid) unit group. The third row will
be saved as a new analyte, since this method+analyte combination does not
currently exist in the database. The fourth row will also lead to a new analyte
since the analyte name and submatrix combination does not currently exist in the
database. Finally, the last row will also be saved as a new analyte. The reason
for this is because the Analyte Name was written as "Almunium (Al)" which does
not currently exist in the database. Thankfully, EnviroData [provides a way of
setting analytes as aliases of one
another](../how_to/analytes_recipes.html#make-an-existing-analyte-into-an-alias-of-another-analyte), should there be a typo that
you are especially suspectible to making.

## Related Reading
- [Explanations - Units](./units)
- [Tutorial 4 - Analytes and Guidelines](../tutorials/tutorial_4)