Configuring BLOB Caching for SharePoint Web Application
BLOB Caching is a feature that isn't well known in SharePoint but serializes large objects to disk on the Web Front Ends to avoid database round-tripping. BLOB Caching would prove beneficial for those who work with large file sizes as this improves page delivery time as cache stores files on front-end server and reduces database traffic. You need to enable BLOB Caching you need to edit your web.config file and changes will be applied to all site collections within the web application.
BLOB is Binary Large Object. here are the steps......
Open web.config file of your Web Application.
You can locate web.config file's location from IIS Manager.