Explanation
Assignment rules are tools that allow administrators to automatically route records to users or queues based on certain criteria. For example, an assignment rule can assign cases to different queues based on case priority, origin, type, or other fields. Assignment rules can be triggered when records are created manually, via email, web, or API. Assignment rules consist of multiple rule entries that define the criteria and actions for each assignment scenario. References:
https://help.salesforce.com/s/articleView?id=sf.customize_leadrules.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.customize_casesupport_assign.htm&type=5

Explanation
The AppExchange is an online marketplace where customers can find apps, components, consultants, developers, and more to extend Salesforce functionality or solve specific business challenges. Some of the actions that can be accomplished via AppExchange are finding certified developers and consultants who can help with custom development or implementation projects; installing industry-specific solution templates that provide preconfigured apps, dashboards, reports etc., for various industries such as manufacturing or healthcare; downloading free tools or components that enhance productivity or user experience; browsing reviews or ratings from other customers who have used certain products or services; etc. References:
https://appexchange.salesforce.com/

Explanation
Maximum invalid login attempts, password complexity requirements, and number of days until expiration are three password policies that an administrator can configure to encourage employees to choose secure and appropriate passwords for their Salesforce accounts. Maximum invalid login attempts determines how many times a user can enter an incorrect password before being locked out of Salesforce. Password complexity requirements determine how complex a user's password must be based on criteria such as length, case sensitivity, alphanumeric characters, etc. Number of days until expiration determines how often users must change their passwords. References:
https://help.salesforce.com/s/articleView?id=sf.security_password_policies.htm&type=5

Explanation
To share report folders with different groups of users with different levels of access, an administrator can use folder sharing settings under setup. Folder sharing settings allow administrators to share report folders with public groups, roles, roles and subordinates, territories, or portal roles with view or edit access. In this case, the administrator can share the Helpdesk folder with Support Agents with view access so they can run Helpdesk reports but not edit them; and share the R&D folder with Support Managers with edit access so they can view and edit R&D reports. References:
https://help.salesforce.com/s/articleView?id=sf.reports_builder_folders_sharing.htm&type=5

Explanation
To make a tab hidden in the All App Launcher or visible in any app, but still allow a user to view records that would normally be found under this tab, the administrator should use Tab Settings on a profile. Tab Settings control the visibility and default behavior of tabs for each app in an org. The administrator can set a tab to Hidden, which means it will not appear in any app or in the All App Launcher, but users can still access records via other means such as search or reports. Object Permissions, App Permissions, and Org-Wide Defaults are not related to tab visibility. References:
https://help.salesforce.com/s/articleView?id=sf.customize_tabs.htm&type=5