A Trailhead Playground is a free, online learning environment that allows you to try out Salesforce features and apps. You can use a Trailhead Playground to test out an app from the AppExchange before you install it in your production org.
A sandbox is a copy of your production org that you can use to test changes and new features. You can install an app from the AppExchange in a sandbox to see how it works in your environment.
Testing an app in a production org is not recommended, as it could affect your live data. Checking edition compatibility is important, but it is not a way to try out an app.

To make it easy for approvers to respond to approval requests, the administrator should configure three settings:
Update the organization's chatter setting to allow approvals, which enables approvers to approve or reject requests from chatter feeds or email notifications Enable the organization's Email approval response setting, which allows approvers to reply to approval request emails with keywords such as APPROVE or REJECT Add the Items to approve component to the approvers home page, which shows a list of pending approval requests that can be acted upon with one click Specifying initial submission actions within the approval process will not affect how approvers respond to requests. Creating a flow to automatically approve all records will bypass the approval process altogether. Reference: https://help.salesforce.com/s/articleView?id=sf.approvals_considerations.htm&type=5 https://help.salesforce.com/s/articleView?id=sf.approvals_email.htm&type=5 https://help.salesforce.com/s/articleView?id=sf.approvals_one_click.htm&type=5

To show a component that shows LinkedIn data only to sales users when they are on their mobile phones, the administrator should filter the component visibility with two conditions:
User > Profile > name = sales User, which checks if the user's profile name is "sales User" Form Factor = phone, which checks if the user's device is a phone Filtering with view or role will not achieve the desired result. Reference: https://help.salesforce.com/s/articleView?id=sf.app_builder_page_visibility_rules.htm&type=5

Knowledge is a feature that can be used to meet this requirement. Knowledge allows users to create, manage, and share articles that provide information and solutions for common issues or questions. Data categories can be used to organize articles into different topics and make them easier to find and access. Users can view related articles from the Case page layout based on the data category of the case. Reference: https://help.salesforce.com/s/articleView?id=sf.knowledge_overview.htm&type=5 https://help.salesforce.com/s/articleView?id=sf.knowledge_categories.htm&type=5

Creating a dashboard with the running user set as someone who can see all opportunities is a way to create an enterprise-wide dashboard of all open opportunities in the pipeline without changing any sharing settings. The running user determines what data is displayed on the dashboard based on their access level and permissions; if the running user can see all opportunities, then the dashboard will show all opportunities regardless of who views it. Updating the dashboard folder settings to manager for the sales reps role does not create an enterprise-wide dashboard; it only controls who can access the dashboard folder, not what data is displayed on the dashboard. Adding a filter to the dashboard to filter the opportunities by owner role does not create an enterprise-wide dashboard either; it only shows opportunities owned by users in certain roles, not all opportunities. Building individual dashboards for profiles that need to see the enterprise results is not a feasible solution; it would require creating multiple dashboards for different profiles and maintaining them separately, which is inefficient and redundant. Reference: https://help.salesforce.com/s/articleView?id=sf.dashboards_running_user.htm&type=5