Knowledge of Salesforce User Licenses and its Types

The following license types are available for Salesforce users

Standard User Licenses
Chatter User Licenses
Experience Cloud User Licenses
Service Cloud Portal User Licenses
Sites and Site.com User Licenses
Authenticated Website User License

The following license types are available only for orgs that use a Customer Portal or partner portal.

Customer Portal User Licenses
Customer Portal — Enterprise Administration User Licenses
User Licenses

If you don’t have a Customer Portal or partner portal but want to share information with your customers or partners, Experience Cloud User Licenses.

Types of User Licenses:

Salesforce

it is used for full access to standard CRM and AppExchange apps.
This is available in all the Salesforce editions.
The Salesforce license type is the Standard user license designed for the users who need complete access to the standard CRM and Salesforce AppExchange applications.

Knowledge Only User

The license is available in the Enterprise, Unlimited, and Performance editions.
need access to the Salesforce Knowledge app
This license includes authorization of different tabs, such as Articles, Article Management, Home, Reports, Chatter, Files, Profile, Custom objects, and custom tabs.
It also includes the knowledge-only profiles that provide access to the Article Tabs using the “View Article” user permission.
The user profiles should have “Manage Articles” permission to view and User the Article Management Tab.

Don't forget to check out: Salesforce Checkout: Manage Your Subscription & Buy Licenses

Identity Only

It Provides extra licenses for employees to access only identity services, such as single sign-on (SSO)

External Identity

Grants access to Salesforce Customer Identity, which enables customers and partners to self-register, login, update their profile, and securely access the web and mobile apps with a single identity.

Salesforce Platform

Users with a Salesforce Platform user license can access all the custom apps in your organization.
This license is available in Enterprise, Unlimited, Performance, and Developer Editions.
With the license, the users can access the core platform functionalities, e.g., accounts, contacts, dashboards, reports, and documents.
It does not provide access to opportunities or sales forecasts. It also does not authorize some permissions and standard apps, which also include the standard tabs and objects.

Force.com — App Subscription — Grants users access to a Lightning Platform Light App with 10 custom objects and 10 custom tabs or Lightning Platform Enterprise App with 10 custom objects and 10 custom tabs. CRM functionality isn’t included.

Company Community User — This license is an internal user license for employee communities. Company Community users have read-only access to Salesforce Knowledge articles. They can also:

Access up-to 10 custom objects and 10 custom tabs
Use Content, Ideas, Assets, and Identity features
Use activities, tasks, calendar, and events
Have access to accounts, contacts, cases, and documents

Developer — This license provides access to development tools and environments. It comes with one Developer sandbox, one scratch org, and access to the Dev Hub. The development environments provide access to Salesforce features. With a Developer sandbox, you can use all the features that exist in the production org.

Chatter Free License

The chatter-free license is designed for those users who want to access chatter only without having the Salesforce license.
The users can access the standard chatter features such as profiles, groups, and files. The users are not allowed to access any Salesforce object or data.
The chatter-free users cannot see the Salesforce tabs like other Salesforce users.

Chatter External

The chatter external license is for users who are outside of the company’s email domain.
Chatter external users can be known as customers.
The users can access the group’s information in which they are invited and can also interact with other users within the group.

Guest User

The Guest user license is designed for the public users who want to access the force.com site or Salesforce Sites.
These public users can also access the public pages in the communities if the Communities option is enabled.
The license is available for the Developer, Enterprise, Unlimited, and Performance Editions.
To find the Number of User License are available in the organization then follow these Step: Setup -> Quick Find Box -> Company Setup -> Company Information