Some databases are composed of multiple meshes, often called domains or blocks. The Index select operator attributes window calls these submeshes blocks. Often when examining a database, you might want to look at only one block at a time. By default, the Index select operator is applied to all blocks in the database. This means that each index range is applied to each block in the database and will probably result in an image featuring several small chunks of cells. When the Index select operator is set to apply to just one block, the index ranges are relative to the specified block. To make the Index select operator apply to just one block, click on the Block radio button and type a new block number into the Block text field.