What is SCORM?
The Sharable Content Object Reference Model (SCORM) defines a Web-based learning "Content Aggregation Model (CAM)" and "Run-Time Environment" (RTE) for learning objects. In essence, the CAM defines how to aggregate, describe and sequence learning objects and the RTE defines the run-time communication and data to be tracked for learning objects. SCORM is a collection of specifications adapted from multiple sources to provide a comprehensive suite of e-learning capabilities that enable interoperability, accessibility and reuse of Web-based learning content. 

The work of the ADL Initiative to develop SCORM is also a process to knit together similar groups and interests.  This reference model aims to coordinate emerging technologies and commercial and public implementations. The SCORM applies current technology developments to a specific content model by producing recommendations for consistent implementations to the vendor community. 

SCORM is built upon the work of the Aviation Industry Computer-Based Training (CBT) Committee (AICC), the IMS Global Learning Consortium, the Institute of Electrical and Electronics Engineers (IEEE), the Alliance for Remote Instructional Authoring and Distribution Networks for Europe (ARIADNE) and others to create one unified "reference model" of interrelated technical specifications and guidelines that meet Department of Defense (DoD) high-level requirements for Web-based learning content.

What's in SCORM?
SCORM consists of four distinct "books" that contain the critical elements of SCORM as follows:

The SCORM Overview book contains high-level conceptual information, the history, current status and future direction of ADL and SCORM and an introduction to key SCORM concepts.

The SCORM Content Aggregation Model (CAM) book describes the components used in a learning experience, how to package those components for exchange from system to system, how to describe those components to enable search and discovery and how to define sequencing rules for the components. 

The SCORM Run-Time Environment (RTE) book describes the Learning Management System (LMS) requirements in managing the run-time environment (i.e., content launch process, standardized communication between content and LMSs and standardized data model elements used for passing information relevant to the learner’s experience with the content). 

The SCORM Sequencing and Navigation (SN) book describes how SCORM conformant content may be sequenced to the learner through a set of learner-initiated or system-initiated navigation events. 

The branching and flow of that content may be described by a predefined set of activities, typically defined at design time.

What does SCORM allow e-learning to do for learners?
SCORM allows for scalable, reusable, sharable course content; discoverable learning content (enables interoperable repositories); the ability to find and move entire courses; vendor support for SCORM conformant COTS products; and, the development of adaptive learning systems that can assemble content to meet the learner's needs "on the fly."

The statements above come from the FAQ section of the ADL website:

http://www.adlnet.gov/scorm/index.aspx