> ## Documentation Index > Fetch the complete documentation index at: https://docs.goguardian.com/llms.txt > Use this file to discover all available pages before exploring further. # Overview > How GoGuardian Admin filtering works, what tools are available, and how to decide which approach fits your district. GoGuardian Admin gives you two filtering methods: policy-based filtering for managed student devices and DNS filtering for any device on your school network. Both methods use category-based rules, but they apply at different layers and serve different coverage needs. Custom Groups let you apply a specific policy to a set of students outside your directory structure. Filtering Policies list in GoGuardian Admin ## Review Filtering Methods ### Policy-Based Filtering Policy-based filtering applies through the GoGuardian app or extension installed on a managed device. It follows the student regardless of location — on campus, off campus, or at home — based on the active [filtering context](/products/admin/filtering-contexts) for their session. Use policy-based filtering when: * Your district manages student devices with GoGuardian installed * You need YouTube-level controls: channels, videos, keywords, categories, and playback settings * Filtering should follow the student off campus or at home * Different students need different filtering rules at the same time ### DNS Filtering DNS filtering applies at the network level. It covers any device that connects through a filtered network — including BYOD, guest, and unmanaged devices — without requiring the GoGuardian app or extension to be installed. Use DNS filtering when: * Your district hosts guest or BYOD networks that need filtered access * You need a network-level baseline for unmanaged or personal devices on campus * You want to supplement managed-device filtering with coverage that applies regardless of device type DNS filtering does not support YouTube-level filtering rules such as channel, video, keyword, or playback settings. Use policy-based filtering for those controls. ## Understand Custom Groups Custom Groups are a targeting mechanism, not a separate filtering method. They let you apply a specific filtering policy to a set of students regardless of their assigned organizational unit. Use them when directory-based policy assignment does not match your filtering intent. Common use cases: * Students who need focused browsing conditions during testing or a specific event * Temporary restrictions that should expire automatically on a set date * A blanket behavior change for a cohort that does not map to an existing OU ## Resources Review the policy model for managed-device filtering. Configure network-level filtering for BYOD, guest, and unmanaged devices. Apply filtering exceptions outside your directory structure. Review how GoGuardian Admin determines which filtering behavior applies in a given session.