Catalogs
Catalogs are custom-defined listings of objects belonging to one object type. A catalog displays a collection of objects of a specific Object Type. In contrast, a view is used to display and edit data contained in one of the objects of the Object Type.
Catalogs perform these basic functions:
Objects Overview
Catalogs provide a concise overview of business objects. They can be used to arrange, sort and filter information for maximum display efficiency.
The administrator / customizing person may choose to make only some of the information (contained in objects of a particular business object type) available to some users.
For instance, using the Person business object available to all users, the administrator can create catalogs such as the ones below and make them available to the interested users only.
Email addresses with just names and addresses.
Phone lists.
All contact information for persons in a particular location, etc.
Search
Catalog is the place where catalog searches are conducted.
Entry point for object editing and other operations
Context menu in a catalog provides important tools for working with business objects (edit, create, copy etc.).
In reference catalogs, inplace editing may be enabled on some columns. This way attribute values can be changed without the need to open the object in an editor.
A standard catalog consists of the following parts:

Hamburger-icon (A)
Calls a menu where you can launch system actions and change the catalog mode.
Catalog mode switch
Choose the desired catalog layout. Note that not all the existing catalog modes may be available for a given catalog.
System actions
A set of system actions. This set corresponds with the actions in the right-click menu. Note that the menu changes dynamically according to the current selection.
Allows you to perform an ad hoc search for one or more keywords in catalog attributes.
The Reset and Refresh controls of the Advanced Search Panel.
Advanced Search Panel display control (D)
Click to expand the Advanced Search Panel. Here you can select a specific Search View and define a simple or complex search condition for the catalog data.
Catalog data (E)
Catalog objects displayed in one of the Catalog layouts.
Catalog controls (F) (G) (H)
These Control buttons enable you to perform some basic catalog operations.
Notes:
The above description refers to a catalog in the table view mode.
Some actions may be customized specifically just for a particular catalog.