Explanation
Standard objects are objects that are included with Salesforce by default, such as Account, Contact, Lead, Opportunity, etc. They have predefined fields and functionality that support common business processes.
Custom objects are objects that you create to store information that is specific to your organization or industry.
You can create new standard objects using the Object Manager in Setup. References:
https://trailhead.salesforce.com/en/content/learn/modules/data_modeling/standard_and_custom_objects

Explanation
Two options that should be added to Lightning record pages to make sales reps aware when they are speaking with high-profile customers are:
Custom Component, which can display a custom message or icon on the record page based on certain criteria such as account rating or industry. For example, an administrator can create a custom Lightning Web Component that shows a star icon on account record pages if account rating is Hot or Warm.
Component Visibility Filter, which can control when a component is visible on a record page based on field values of that record. For example, an administrator can add a component visibility filter to an existing component such as Path or Highlights Panel that makes it visible only if account rating is Hot or Warm. Highlight Panel, Action and Recommendations, and Rich Text Area are not options that can be used to make sales reps aware when they are speaking with high-profile customers. References:
https://developer.salesforce.com/docs/component-library/documentation/en/lwc/lwc.create_components
https://help.salesforce.com/s/articleView?id=sf.dynamic_forms_component_visibility.htm&type=5

Explanation
Screen flow allows you to create a form that collects user input and performs actions based on that input. You can use screen components to display questions and instructions, and use flow logic to update records or send notifications.
References: https://trailhead.salesforce.com/content/learn/modules/screen-flows/get-started-with-screen-flows
https://help.salesforce.com/s/articleView?id=sf.flow_builder_overview.htm&type=5

Explanation
To make a quick action available on the Salesforce mobile app, you need to add it to the Salesforce Mobile and Lightning Experience Actions section of the page layout. You can use the Page Layout Editor to drag and drop the quick action onto the section.
References: https://help.salesforce.com/s/articleView?id=sf.actions_in_lex.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.customize_page_layouts.htm&type=5

Explanation
Campaign influence is a feature that allows users to track how campaigns have influenced opportunities and measure the return on investment (ROI) of marketing efforts. Users can see which campaigns have influenced an opportunity on the related list and assign different attribution models to calculate the campaign influence.
References: https://help.salesforce.com/s/articleView?id=sf.campaigns_influence.htm&type=5