What Command Argument do

<asp:Label ID="lblactive" runat="server" Text='<%# Convert.ToBoolean(Eval("IsActive")) ? "Yes" : "No"%>'
                                                                                             Visible="false"></asp:Label>
                                                                                         <asp:ImageButton ID="imgActive" runat="server" ImageUrl="~/Images/Active.png" Visible='<%# Eval("IsActive") %>'
                                                                                             Width="24px" Height="24px" OnCommand="imgActive_Command" CommandName="Active"
                                                                                             CommandArgument='<%# Eval("UserRoleFundFamilyID") %>' />
                                                                                         <asp:ImageButton ID="imgInActive" runat="server" ImageUrl="~/Images/InActive.png"
                                                                                             Visible='<%# !Convert.ToBoolean(Eval("IsActive")) %>' Width="24px" Height="24px"
                                                                                             OnCommand="imgActive_Command" CommandArgument='<%# Eval("UserRoleFundFamilyID") %>'
                                                                                             CommandName="InActive" />
                                                                                     </ItemTemplate>