Indexing the content of your PC helps you get faster results when your searching it for files, emails, or other local content.
The search index only includes your selected locations by default. These locations can be filtered for what file types (extensions), file properties, and file contents you want indexed.
Starting with Windows 10 build 18267, Microsoft added a new Enhanced Mode feature to improve search indexing that enables Windows to search all your folders and drives, instead of limiting search (Classic) to your documents, pictures, videos, and desktop by default.
To exclude a folder from search, you can add it to the Excluded Folders list.
This tutorial will show you how to add or remove Excluded Folders for Search Indexer for your account or all users in Windows 10.