DXF, Drawing Interchange Format, or Drawing Exchange Format, is a tagged data representation of AutoCAD drawing file. Each element in the file has a prefix integer number called a group code. This group code actually represents the element that follows and indicates the meaning of a data element for a given object type. DXF makes it possible to represent almost all user-specified information in a drawing file.
Files with ICO extension are image file types used as icon for representation of an application on Microsoft Windows. These come in different size, colour support and resolution to suit the requirements of the display. Another similar image file format on Microsoft Windows is .CUR for cursor representation and defines a hotspot in the image header. On MacOS, ICNS file formats serve the same purpose as ICO files. Several online websites as well as applications provide the feature of creating such files and convert other image formats such as BMP, PNG, etc. to icon file format. The official IANA registered Internet media type for ICO files is image/vnd.microsoft.icon.
You can also convert DXF into many other file formats. Please see the complete list below.