Data file formats
44 formats in this category.
Data formats hold structured information, from spreadsheets exported as text to generic binary blobs whose meaning depends on the program that made them.
Structured, tabular and opaque
Data formats hold information rather than documents or media. Tabular formats (CSV, and spreadsheet exports) lay data out in rows and columns and are the lingua franca of data exchange. Structured formats (JSON, XML) nest data into records and fields for APIs and configuration. Database and app-store formats (SQLite, .db) keep many records in one indexed file that a program queries directly.
Then there are opaque binaries: generic .dat, .bin and .cache files whose meaning depends entirely on the program that wrote them. There is no universal way to read these; the honest first step is to inspect the bytes to see whether a known format is hiding under a generic name.
Reading a mystery data file
When you meet an unfamiliar data file, check its signature before anything else. A hex viewer, or dropping the file into an in-browser identifier, reveals whether those first bytes match a known format such as SQLite or ZIP. If they do not, the file is likely a program's private format, and only that program can make sense of it.