Different Defintions of BIM

BIM (Building Information Modeling) is an intelligent 3D model-based process that gives architecture, engineering, and construction (AEC) professionals the insight and tools to more efficiently plan, design, construct, and manage buildings and infrastructure.
(Source: Autodesk)

Building information modeling (BIM) is a process involving the generation and management of digital representations of physical and functional characteristics of places. Building information models (BIMs) are files (often but not always in proprietary formats and containing proprietary data) which can be extracted, exchanged or networked to support decision-making regarding a building or other built asset. Current BIM software is used by individuals, businesses and government agencies who plan, design, construct, operate and maintain diverse physical infrastructures, such as water, refuse, electricity, gas, communication utilities, roads, bridges, ports, tunnels, etc.
(Source: Wikipedia)

Some say BIM is a type of software. Some say BIM is the 3D virtual model of buildings. Others say BIM is a process or BIM is nothing more than the collection of all building data organized into a structure database easy to query both in a "visual" and a "numerical" way. It is safe to say that BIM is all the above and some more… Now let’s see BIM explained in laymen’s terms. When it comes to BIM everything starts with a 3D digital model of the building. This model, however, is way more than pure geometry and some nice textures cast over it for visualization. A true BIM model consists of the virtual equivalents of the actual building parts and pieces used to build a building.
(Source: Graphisoft)

This may come as a surprise, but BIM isn’t new. It first appeared as early as 1962, when Douglas Engelbart wrote his paper “Augmenting Human Intellect: A Conceptual Framework” and described architect entering specifications and data into a building design and watching a structure take shape—a concept very similar to modern parametric modeling.
(Source: Engineering.com)

Further Reading:  BIM Structural Engineering Curriculum (Autodesk)

                             Understanding Building Information Modeling

                             Origins of BIM

About Dynamic Block

Dynamic blocks contain rules, or parameters, for how to change the appearance of the block reference when it is inserted in the drawing.

With dynamic blocks you can insert one block that can change shape, size, or configuration instead of inserting one of many static block definitions. For example, instead of creating multiple interior door blocks of different sizes, you can create one resizable door block.

You author dynamic blocks with either constraint parameters or action parameters.

Note:
Using both constraint parameters and action parameters in the same block definition is not recommended.

Checkout my online presentation about dynamic block tutorial embeded on this post. Thanks for reading.