Schematic in PDF form for the GT-I9505, a Samsung model number, at 28.2 MB. The name gives no board revision or other detail, so the exact contents are only confirmed by opening it. Phone service schematics of this kind normally cover the PMIC, charging path, RF section, display and camera connectors, helping a technician trace power rails, find where a short sits and follow signal lines between components. Any PDF reader opens it; check that the board markings on your unit match the drawing before relying on it.
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 @schematic_mobiles. 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.