Sites
A monitoring "site" refers to a single location where observations are recorded or created. This could be a collection of sensors grouped together like a weather station measuring temperature, wind speed, and atmospheric pressure. Or, it could simply be a lab worker going out to the same place in a river and measuring the water level. Typically, this is a fixed physical location where one or more instruments are deployed for making measurements.
A site encompasses both the physical location and the metadata describing the site such as site name, site code, any photos of the site, and a key:value tagging system to help you describe that location beyond what's available in the fields provided by the data model and API.
A site is not the physical sensors or instruments that are deployed at the site's location. That metadata lives in the Sensor table of HydroServer's database.
A side note on Thing vs. Site
Given that it is an "Internet of Things" standard, SensorThings uses the term Thing in order to stay as general as possible. In the field of water data management, users are more more often familiar with the term Site as in a monitoring site. Therefore, we've opted to refer to a Thing as Site in all of our user facing applications. But, to strictly follow the SensorThings specification, we've kept SensorThing's original Thing naming in our data model and APIs.
key:value tagging system
Most of the metadata you will need is already supported by HydroServer’s API. However, for organization-specific or custom information, tags offer a flexible way to store additional metadata that doesn’t fit into the standard fields. Tags are extra, customizable, key:value pairs that provide more context or categorization to the data. For example, you might use tags to link to your sites to 3rd party websites: website:https://my-website.com. You can use tags to specify values for additional attributes of a site, or you can point to external websites or URLs where more detailed information about that site might be maintained.