Looking for a clear description of Excel’s .xlsx XML format

Microsoft Excel’s “.xlsx” files are zip files that each contain a set of files. Could someone please provide a link that concisely describes the full structure/syntax/markup/format of the embedded .xml files (the headers are less interesting)? For example, it’s hard to find online explanations on what the c, t, and s elements represent.

What does <> mean?

Yes, it means “not equal”, either less than or greater than. e.g can be read as if x is less than y or x is greater than y then The logical outcome being “If x is anything except equal to y”

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