What is TSV?

CSV with tabs instead of commas, and the better choice more often than people realise. Tabs almost never appear inside a field, so the quoting rules that make CSV parsing miserable largely evaporate. Anything with prose, addresses or European decimals in it is safer as TSV.

What is JSON?

The format the web runs on. Nested objects and arrays, real types, and a syntax small enough to fit on a postcard. It maps badly onto a grid, which is why converting deeply nested JSON to a spreadsheet always involves losing something.