Word Editor is for text documents. Start a blank document or open a .docx, then format it with bold, italics, underline, headings, bulleted and numbered lists, alignment, links, tables and images. It has undo, redo and a word count, and you save the result as .docx or use "Print or save as PDF" through your browser's print dialog. When you open an existing .docx, text, headings, lists, tables, images and links are kept; headers and footers, columns, text boxes, comments, tracked changes and advanced styles are not.
Online Spreadsheet is for numbers and lists. Create a new sheet or open an .xlsx or .csv file, edit cells, work with several sheets and add or remove rows and columns. Common formulas such as SUM, AVERAGE, IF, COUNT, MIN, MAX and ROUND work, and so do their usual Spanish and Portuguese names. Save as .xlsx with values and formulas, or as .csv for the active sheet. Colors, borders, number formats, charts, filters and merged cells are not carried over from an opened file.
PDF Reader is for when you only need to look at a PDF. Zoom in and out or fit to width, jump to a page, search text with highlighted results, select and copy text, follow links and rotate the view. It never changes the file. If you need to mark it up, move on to Annotate PDF; to pull the text out, PDF to TXT.
Read PDF aloud extracts the text of a PDF and reads it with your device's voices. You choose the voice, a speed from 0.8× to 2× and the page to start on, and the part being read is highlighted. The voices and their quality depend on your device and browser, the reading can't be downloaded as MP3, and a scanned PDF needs OCR PDF first so there is text to read.
Use these editors when you need a quick change and don't have office software at hand, for example on a borrowed computer or on your phone. For heavier jobs on PDFs, the PDF tools are a better fit: Edit PDF adds text and images to a page, PDF to Word turns a PDF into an editable document you can then open in Word Editor, and PDF to Excel pulls tables into a spreadsheet you can continue in Online Spreadsheet.
These editors have no cloud and no collaboration: your document lives in the browser tab until you download it. If you close the tab without saving, the work is lost, and the site warns you before closing.