All libraries and documentation are currently in Beta. Content and features are subject to change.


For questions around the concepts and terminology specific to Solid, refer to


An Access Control List. ACL entry specifies the access granted to an agent to a resource. See also Access Modes.


A user. Agent typically refers to a person but could also refer to other users, e.g., applications, bots.

Access Modes

The types of access that have been granted by an ACL: Read Access, Append Access, Write Access and/or Control Access.

Append Access

When an ACL grants Append access, the grantee is allowed to add data to the applicable Resource, but it does not grant them access to remove any.

Control Access

When an ACL grants Control access, the grantee is allowed to see and change who has access to the applicable Resource.


A special type of Resource that can contain other Resources or Containers, much like folders on your file system.

For example, given a Resource at, both and are Containers.

Default access

Rules defining Access Modes that apply not to the Container Resource directly, but are inherited by its children, their children if applicable, and so forth.

Fallback ACL

If a Resource does not have a Resource ACL:, the Fallback ACL is the ACL of the Container closest to that Resource that has its own Resource ACL. Only the Default access rules in the Fallback ACL apply.


Storage location for your data. You manage the access to data stored in your Pod.


The thing sent to you when you type a URL into a web browser.

Resource ACL

The ACL that applies to a given Resource. If none exists, the Fallback ACL applies.

Read Access

When an ACL grants Read access, the grantee is allowed to view the contents of the applicable Resource.


Set of Things that are stored in a specific Resource.


A data entity, e.g., a person. A Thing is associated with a a set of data or properties about the Thing, e.g., name.


A URL that identifies a user or other Agent. The Resource found at the WebID can provide more information about this Agent, such as the location of their data.

Write Access

When an ACL grants Write access, the grantee is allowed to change the contents of the applicable Resource. Granting Write access automatically also grants Append Access.