Collections are temporary tables that store session-specific data in memory. They can be used for various purposes in APEX applications. Some uses of collections are:

• You insert, update, and delete collection information using PL/SQL API APEX_COLLECTION. This API provides several procedures and functions to manipulate collections and their members.
• Use collections to temporarily capture one or more nonscalar values. For example, you can use collections to store the results of a query, the values of page items, or the selections of a report.
• Collections can be accessed, manipulated, or processed during a user’s specific session. For example, you can use collections to pass data between pages, perform calculations on collection members, or create reports based on collections.

Collections do not enable you to store rows and columns in the current session into database tables. Collections are stored in memory and are not persistent across sessions.

REST Data Source Synchronization is a feature that enables developers to automatically sync the contents of a local table with the data from an external REST service. To execute REST source synchronizations on schedule, the CREATE JOB privilege must be granted to the application’s parsing schema, which allows APEX to create a DBMS_SCHEDULER job for each scheduled synchronization task. If the local table is not in sync with the Data Profile, which defines the columns and data types of the REST service response, Data Synchronization continues to work for columns present in both the table and the Data Profile (other columns are ignored). However, APEX generates SQL DDL statements to sync table columns back to the Data Profile, which can be added to the application as supporting objects. Verified References: Managing Data Synchronization - Oracle Help Center, Synchronize Data from REST Services to Local Table - Oracle Blogs

Object Browser is a utility in SQL Workshop that enables developers to browse, create, and edit objects in a database. Some of the actions that you can perform using Object Browser are:

• Browse database objects of the current schema. You can view the details of an object by selecting it from the Object Tree and then clicking the different object detail tabs.
• Create a lookup table based on a column in the current table. You can use the Create Lookup Table option in the Column Details tab to create a new table that stores the distinct values of the selected column and a foreign key constraint to reference it. You cannot restore dropped database objects, create and run SQL scripts, or export and import SQL scripts using Object Browser. You can use other utilities in SQL Workshop to perform these actions, such as Recycle Bin,SQL Commands, and SQL Scripts. Verified References: [Managing Database Objects with Object Browser - Oracle Help Center], [Creating Lookup Tables - Oracle Help Center]