A bond line structure is less cluttered drawing than a condensed structural formula. However, to understand the simplified bond-line structure, the reader has to mentally add many more features to comprehend the overall structure.
It is another way of structural representation of organic compounds. Here, every bond is represented as a line in zig-zag manner. If not specified, every terminal is assumed to be a methyl (-CH3) group and every junction is assumed to be a methylene (-CH2) group.
Example :