Explanation
The Approvals component in Oracle APEX is a feature that allows developers to create approval workflows for business processes that require human intervention or decision making. The Approvals component consists of three main elements: Tasks, Task List Page, and Task Details Page. The Unified Task List is a page type in the Create Page Wizard that is used to create a summary of tasks that functions like an inbox for end users.
The Unified Task List displays all tasks assigned to or created by an end user along with their status, priority, due date, etc. End users can filter, sort, search, view details, and perform actions on tasks from this page.
Verified References: [Using Approvals - Oracle Help Center], [Creating a Unified Task List Page - Oracle Help Center]

Explanation
To create a REST Enabled SQL Reference, you need to meet the following requirements:
Install Oracle REST Data Services (ORDS) 19.x or later. ORDS is a Java application that enables developers to create, publish, and manage RESTful web services for Oracle databases1.
Activate REST Enabled SQL for the target schema on the remote database. REST Enabled SQL is a feature of ORDS that allows you to execute any SQL or PL/SQL through a REST endpoint. You need to enable this feature for the schema that contains the data you want to access2.
Configure and enable the REST Enabled SQL service feature. This is a workspace-level setting that allows you to use REST Enabled SQL references in your APEX applications. You need to specify a path prefix and a secret for the REST Enabled SQL service3.
You do not need to set up any remote database, as long as it meets the ORDS and REST Enabled SQL requirements. You can use any Oracle database or MySQL database as a remote data source2.

Explanation
When you enable the Save Public Report attribute for an interactive grid, end users can save their report preferences as either private or public reports. Private reports are only visible to the user who created them, while public reports are visible to all users who have access to the interactive grid. You can also specify an authorization scheme to control who can save public reports. Verified References: Managing Interactive Grids
- Oracle Help Center, [Interactive Grid Attributes - Oracle Help Center]

Explanation
A facet is a type of component that provides a set of display values and return values for a faceted search region or a smart filters region. A facet can be based on either static values or dynamic values from a list of values (LOV). A facet can also have different display styles depending on its type and settings. Three of the types of facets that you can create in APEX are:
Range: A range facet displays numeric values in either buckets or sliders that users can select or adjust to filter the search results. A range facet can have either static values or dynamic values based on an LOV or SQL query.
Checkbox Group: A checkbox group facet displays multiple options that users can select or deselect to filter the search results. A checkbox group facet can have either static values or dynamic values based on an LOV or SQL query.
Input Field: An input field facet displays a text field that users can enter text to filter the search results.
An input field facet does not have any values but uses an operator to compare the user input with the data.

Explanation
An authentication scheme is a rule that determines if a user is authorized to access a specific component or feature of an application, such as a page, region, button, item, etc. An authentication scheme type defines how users are authenticated when they access an application. The authentication scheme type that supports authentication with social networks and enterprise identity providers that support OpenID Connect or OAuth2 standards is Social Sign-In. Social Sign-In supports authentication with Google, Facebook, and other social networks that support these standards. The other authentication scheme types do not support authentication with social networks or enterprise identity providers. They are:
HTTP Header Variable: Authenticate users externally by storing the username in a HTTP Header variable set by the web server.
SAML Sign-In: Delegates authentication to the Security Assertion Markup Language (SAML) Sign In authentication scheme.
Open Door Credentials: Enable anyone to access your application using a built-in login page that captures a user name. Verified References: [Understanding Preconfigured Authentication Schemes - Oracle Help Center], [Social Sign-In - Oracle Help Center]