XLS files are the original file format for Microsoft Excel workbooks. These files store data in a structured, spreadsheet-like format.
Understanding XLS Files
The XLS file extension signifies the older, binary file format that was used by Microsoft Excel before the introduction of the newer XLSX format. Here's a breakdown:
Key Characteristics of XLS Files
- Original Format: XLS was the primary format for Excel files for many years.
- Binary Format: Unlike the newer XLSX format, XLS files use a binary structure.
- Formatting: They define the appearance and layout of the spreadsheet, including cell styles, fonts, and colors.
Transition to XLSX
The XLS format has largely been superseded by XLSX, a modern, XML-based format, which was launched with Office 2007.
| Feature | XLS | XLSX |
|---|---|---|
| Format | Binary | XML-based |
| Introduction | Prior to Office 2007 | With Office 2007 and later |
| Functionality | Core spreadsheet data and format | Core spreadsheet data and format, more open and flexible |
Why the Change?
- Modernity: XLSX files are based on XML, making them more open, flexible, and easier to work with programmatically.
- File Size: XLSX files are often smaller than XLS files because of the XML structure.
- Security: XML offers an increased level of security and resistance to malicious content.
- Evolution: The XLSX format also led to the development of macro-enabled files with an extension of XLSM.
Practical Implications
- While XLS files can still be opened by modern versions of Microsoft Excel, it's generally recommended to save new workbooks as XLSX to benefit from improvements in file handling.
- You may encounter older documents that are saved as XLS files, which can be converted to XLSX if needed.
In Summary: XLS files represent the legacy file format for Microsoft Excel, defining the structure, content, and appearance of spreadsheets. Though still usable, the newer XLSX format is the current standard, thanks to its enhanced features and greater flexibility.
