Every theme (except image and grid themes) has a data table attached to it, with one row in the table for each feature (shape). The table has a fixed column structure; each column holds a particular type (character string, number (with or without decimal places), or date) of data and has a fixed length. The rows are called 'records' and the columns are called 'fields'. The boxes in the grid formed by the intersection of records and fields are called 'cells' (a cell is one record's value at a field). Point, line, and polygon themes all have tables. If you look at a theme's table (you can open a theme's table by making it the active theme in a View and clicking the Open Theme Table button on the View's button bar) you will notice that the first column is called 'Shape'. You cannot change the values in this field; they represent the shape feature that the data in the other columns are related to. All the other columns are normal 'tablular' (table) data and can be edited. If your theme was originally an ARC/INFO coverage, you will notice that there are some additional fields (Area, Perimeter and a couple of IDs for polygon and point shapefiles; Fnode, Tnode, Rpoly, Lpoly, Length, and a couple of IDs for line files). These fields are system fields that ARC/INFO calculates automatically during the BUILD process; generally you don't need to enter anything into them.
