What is XML?

Description

XML (eXtensible Markup Language) is a universal text format for storing and exchanging data. Its flexibility and readability have made XML a standard in many fields: from web development to accounting and data exchange between systems.

1. XML basics: structure and purpose

XML is not a programming language — it's a markup language that allows you to describe the structure of data. The main unit of XML is an **element**, which has an opening and a closing tag.

<person>
 <name>John Doe</name>
 <email>john.doe@example.com</email>
</person>

• User-defined tags: you create the tag names yourself.
• Data is structured hierarchically.
• Text format: readable by both humans and machines.

2. Advantages of XML in business and IT

XML is an ideal solution when you need to:

• transfer data between different systems (e.g., CRM ↔ ERP),
• store complex information in a structured format,
• create configuration files for programs,
• import/export information from databases.

It is used in:

• banking (e.g., SEPA XML),
• electronic reporting,
• API services,
• online stores (e.g., XML product feeds).

3. XML validity and schemas

For an XML document to be correctly processed by other systems, it must be **valid**. Validity is checked through:

• **DTD** (Document Type Definition)
• **XSD** (XML Schema Definition)

**Example of defining an element type:**

<xs:element name="Price" type="xs:decimal"/>

An XML file that does not conform to the schema may be rejected by the receiving system.

4. XML in web development and integrations

In web development, XML is used for:

• creating Sitemap files (sitemap.xml) for SEO,
• data transfer via API (especially in SOAP),
• storing configurations (e.g., web.config in .NET).

<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
 <url>
  <loc>https://example.com/home</loc>
  <lastmod>2025-07-18</lastmod>
  <changefreq>weekly</changefreq>
  <priority>1.0</priority>
 </url>
</urlset>

This file helps search engines index your site better.

5. XML vs JSON: which is better?

XML is better suited for complex structures with attributes, while JSON is for lightweight REST APIs.

6. XML in combination with Excel

Excel is one of the most common tools for working with tabular data. But it does not support convenient conversion of tables to XML "out of the box."

This is where the custom Excel function TABLETOXML() comes in handy, which automatically creates valid XML code from tabular data in Excel.

**Example:**

*Table in Excel:*

*After applying TABLETOXML():*

<items>
 <item>
  <ID>1</ID>
  <Name>Monitor</Name>
  <Price>120</Price>
 </item>
 <item>
  <ID>2</ID>
  <Name>Keyboard</Name>
  <Price>35</Price>
 </item>
</items>

This is especially useful for generating XML feeds for marketplaces like Rozetka, Prom, Google Merchant.

Conclusion

XML remains an important data exchange standard due to its versatility, readability, and support by a wide range of tools. Thanks to solutions like the TABLETOXML() function for Excel, even users without technical knowledge can easily create XML documents for business, reporting, or integrations.