The standard column class is “Mage_Adminhtml_Block_Widget_Grid_Column”

This class is responsible for adding columns to magneto grid.
This class sets the “renderer” and “filter” for every column in the grid.
Both renderer and filter are very important for every column.
Renderer basically sets the display of column heading i.e date type renderer has to/from date picker.
Filter is used adding filters to the collection.

All full list of filters and renderes can be seen at
Mage_Adminhtml_Block_Widget_Grid_Column_Filter
Mage_Adminhtml_Block_Widget_Grid_Column_Renderer