What is `sections.xml` and `sections.xsd` in the «Customer» module?

[Kodi_Babu (Poongudivanan N)]

How section.xml works…

Kindly advice. Thanks

[dmitry_fedyuk (Dmitrii Fediuk)]

A section.xml file is used to specify data invalidation rules for customers:
devdocs.magento.com/guides/v2.0/extension-dev-guide/cache/page-caching/private-content.html#invalidate-private-content