File formats explained
Understand how each format works, what it is good at, and what breaks it. Foundational reading before you troubleshoot anything.
PDF — the print-perfect container
PDFs pin every glyph to a coordinate on a page. They love fidelity and hate reflow.
DOCX — a zipped XML document
A .docx file is a ZIP of XML parts. Structure is explicit: paragraphs, runs, styles, tables.
XLSX — a grid with formulas
Spreadsheets are two-dimensional arrays of cells. The value on screen is often a formula's result, not the underlying data.
Images and OCR — pixels to text
OCR turns a picture of text into characters. Accuracy depends almost entirely on the input image.