A block is a named group of entities. When you change a drawing library block or internal block, all the drawings in the library that refer to the block are automatically updated. They make creating reports easier, give them consistency, and make them easier to maintain.
There are two kinds of blocks that located in the library but are external to the report and included in it by reference—these are drawing library blocks and internal blocks. These two kinds of blocks allow you to re-use entities.
The distinction between drawing library and internal blocks is that drawing library blocks can be used in any reporting or drawing application, whereas internal blocks are specific to a particular reporting application such as logs, fences, or graphs (that is, “internal” to the application). A log block can be used in any log report in the library, but not in a fence, and so on. A drawing library block does not have this restriction. Also, drawing library and internal blocks are accessed using separate parts of the giNT interface. In all other regards, drawing library and internal blocks operate identically.
Drawing library and internal blocks can be included (or nested) within other drawing library and internal blocks (subject to certain restrictions).
There is a third kind of block which is merely a grouping mechanism within a report. These are called private blocks. A private block does not include anything by reference into a report from outside the report, and doesn’t exist separately from the report. Rather, the entities in the private block are part of the report, but are grouped together in a way that enables you to hide, reveal, or move them together in response to data conditions.
These three kinds of blocks, and how they can be used, are illustrated below:
Working With Blocks Part Two: Drawing Library Blocks https://communities.bentley.com/products/geotechnical1/w/wiki/12372.working-with-blocks-part-2-drawing-library-blocks.aspx
Working With Blocks Part 3: Internal Blocks https://communities.bentley.com/products/geotechnical1/w/wiki/12374.working-with-blocks-part-3-internal-blocks.aspx
Working With Blocks Part 4: Private Blocks https://communities.bentley.com/products/geotechnical1/w/wiki/12378.working-with-blocks-part-4-private-blocks.aspx