File Types: Excel vs CSV
They open in the same app. That’s where the similarities end. As someone who works with large amounts of data (and has made a lot of mistakes), I'm writing this for anyone still fuzzy on the fundamental differences between Excel (.xlsx) and Comma-Separated Values (.csv) files. If you’re expected to automate data flows , please don’t ignore this one. This post is for you! On the surface, these two look like identical twins: Tomayto.xlsx Tomahto.csv But if you look closely, you’ll notice the first difference. If you noticed that Tomayto.xlsx is 7× bigger in Size than Tomahto.csv —you’re right! And here’s the key detail: both files are EMPTY . So, what's going on? They both look the same to us, but the computer sees it differently.