Most formulas need only the values you pass to them. A smaller group reads information supplied by the screen or workflow where the formula runs.
A context function that needs a concrete snapshot fails clearly when that snapshot is unavailable. For example, ResponseStatus() cannot run on a normal calculated field that has no captured HTTP response. Functions whose entries describe an optional value, such as ParentKey(), can return null instead.
Device values
The four device functions use one captured snapshot. This keeps latitude, longitude, location, and timestamp consistent within the same evaluation.
Use them in workflows that capture device data, such as submission-time location recording:
Response values
Use response functions after a workflow has captured an HTTP response:
Response() returns the raw body. A path can extract JSON or XML data, and an optional result type can convert it. See Special functions.
Session values
Session functions help identify the current database, table, record, user, role, browser class, and URL. Use them for labels, routing, permissions-aware presentation, and integration payloads—not as a replacement for server-side access control.
Prompt values
Parameter declares or reads a prompt value. Ask checks whether required inputs are still missing and evaluates its condition after they are supplied. See Ask and parameter functions. 
