Small ZIP archive of 149 KB for a Toshiba Satellite board made by Pegatron, model code CA10BM at revision 2.1. The name does not say what is inside, so it may hold a schematic, a boardview or another service document. Pegatron builds many Satellite mainboards and prints the model and revision on the PCB, so confirm both before using the contents. Files of this kind help technicians trace power rails, find test points and locate components while diagnosing faults.
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 @boardviews. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Built-in OS tools7-Zip