DataGridViewCell

This is the fundamental unit of interaction for the DataGridView
You can access cells by using the Cells collection of the DataGridViewRows class.

dgvDataGridViewRow.Cells(0) 

You can access the selected cells by using the SelectedCells collection

dgvDataGridViewRow.Cells(0) 

DataGridViewCell objects do not control their own appearance and painting features

Value

For a DataGridView that is not databound and not in virtual mode each cell stores its own value

Value (Databound)

For a DataGridView that is databound each cell does not know its actual value and must be looked up in the datasource.
The data type of each cell is automatically changed and this can be seen from the ValueType property.

FormattedValue

The FormattedValueType property determines the type that is used for display.
Most columns use String

Any time the FormattedValue is required the CellFormatting event is fired

If a cell cannot retrieve its formatted value correctly it raises the DataError event.

DataGridViewCellStyle

Always try and set the default cell style for the whole DataGridView control

dgvDataGridView.DefaultCellStyle = 

Dim highlightCellStyle As New DataGridViewCellStyle 
highlightCellStyle.BackColor = Color.Red 

Dim currencyCellStyle As New DataGridViewCellStyle 
currencyCellStyle.Format = "C" 
currencyCellStyle.ForeColor = Color.Green 

With Me.dataGridView1 
    .DefaultCellStyle.BackColor = Color.Beige 
    .DefaultCellStyle.Font = New Font("Tahoma", 12) 
    .Rows(3).DefaultCellStyle = highlightCellStyle 
    .Rows(8).DefaultCellStyle = highlightCellStyle 
    .Columns("UnitPrice").DefaultCellStyle = currencyCellStyle 
    .Columns("TotalPrice").DefaultCellStyle = currencyCellStyle 
End With 

The following are the list of objects and properties that can get or set DataGridViewCellStyle objects

DataGridView.DefaultCellStyle 
DataGridViewColumn.DefaultCellStyle 
DataGridViewRow.DefaultCellStyle 

DataGridView.RowsDefaultCellStyle 
DataGridView.AlternatingRowsDefaultCellStyle 
DataGridView.RowHeadersDefaultCellStyle 
DataGridView.ColumnHeadersDefaultCellStyle 

DataGridViewCell.Style 

DataGridViewColumn.InheritedStyle 
DataGridViewRow.InheritedStyle 
DataGridViewCell.InheritedStyle 

Getting the value of a style automatically instantiates a new DataGridViewCellStyle object if the property has not been previously set.
To avoid creating these accidentally you should check first using the following properties:

DataGridViewColumn.HasDefaultCellStyle 
DataGridViewRow.HasDefaultCellStyle 

DataGridViewCell.HasStyle 

DataGridViewTextBoxCell

This is a specialised type of DataGridViewCell that is used to display a single string of editable text.
When you derive from this class you need to overwrite the Clone method.

Properties

DataGridViewCheckBoxCell

Properties

if (checkboxCell.Value == true) 
{ 
} 

DataGridViewCellTemplate

Cell templates are instances of a DataGridViewCell derived class.

Making changes to the CellTemplate of a column will update the template and update all the cells in that column, refreshing the display if necessary.