Summary datasheet for the tiny15, matching the Atmel AVR ATtiny15 microcontroller, in a small 124 KB PDF indicated by the s suffix. Such abridged editions usually carry only the feature list, pin configuration, register summary and ordering information. It works as a quick pin identification sheet when inspecting an older board fitted with this 8-pin part. Programming procedures, timing data and complete electrical characteristics are found only in the full ATtiny15 datasheet, also present in this set as a separate file.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @datasheet. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.