An 81.4 KB PDF named for the 24C04 with a _3 suffix, probably one of several copies of the same reference sheet. The 24C04 is a 4 Kbit (512-byte) I2C EEPROM, and the name gives no device, board or manufacturer. Expect pin descriptions, address handling, supply range and write-cycle timing. Technicians rely on it when reading or reprogramming settings memory in consumer electronics. Confirm the chip marking matches and make a backup of the original contents before writing with a programmer.
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 @cyberlanelectonik. 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.