An attribute is a label or tag that attaches data to a block. Examples of data that might be contained in an attribute are part numbers, prices, comments, and owners' names. The tag is equivalent to a column name in a database table. The following illustration shows tags for type, manufacturer, model, and cost.
Attribute information extracted from a drawing can be used in a spreadsheet or database to produce a parts list or a bill of materials. You can associate more than one attribute with a block, provided that each attribute has a different tag.
Whenever you insert a block that has a variable attribute, AutoCAD LT prompts you to enter data to be stored with the block. If the block has only constant attributes, attributes whose values do not change, AutoCAD LT does not prompt you for a value when you insert the block.
Attributes also can be "invisible." An invisible attribute is not displayed or plotted; however, the attribute information is stored in the drawing file and can be written to an extraction file for use in a database program.