Groups:
A group consists of a set of users. A group can contain individual users, other groups, or the users in a particular role or territory. It can also contain the users in a particular role or territory plus all the users below that role or territory in the hierarchy.
Queues:
Queues help your teams manage leads, cases, service contracts, and custom objects. Once records are placed in a queue manually or through an automatic case or lead assignment rule, records remain there until they’re assigned to a user or taken by one of the queue members. Any queue member or users above them in the role hierarchy can take ownership of records in a queue. Use queues to route lead, case, and custom object records to a group.
Difference between Public Group and Queue:
| Queue | Public Group |
|---|---|
| Queues are used primary as Owners of records. | Public Groups are used primary for security. |
| Queue is a feature available to salesforce.com users that allows you to integrate prospect assignments with your current salesforce.com workflow. Rather than assigning to a specific user, you can choose to assign leads to a salesforce.com queue and then use your CRM workflow or manual method of distributing leads to sales representatives. | Public Group is kind of team or group of related users, this will help to share the data. |
| Queues are typically used when you want to assign a record to a bunch of users.Using Queues you can assign a record to multiple users, so that any member of the queue can work on the record. It also allows the users to have there separate views. | Group on the other hand are used more for a sharing purpose. They are not the owner of the records like queue, but can share the records in terms of access. |
| Queue can be created for Custom objects and for Case, Lead and Knowledge Article Version. | Public group created can be used across any objects. |