Can we use SLDS in Visualforce page?

You can use the Lightning Design System (SLDS) to build Visualforce pages that match the look and feel of the Salesforce mobile app. To use SLDS, it takes some tweaks in your code and a few things to remember. For the most part, Visualforce code that uses SLDS works without issue.

Yes, you can use Salesforce Lightning Design System (SLDS) in Visualforce pages. It allows you to leverage the modern, scalable CSS framework provided by Salesforce to build visually appealing pages consistent with the Lightning Experience UI. You just need to reference the SLDS static resource in your Visualforce page to use it. Remember to understand and follow Salesforce's best practices for using SLDS with Visualforce to ensure optimal results.