The expression can be traced back to horse racing in the 1700s when goats were used to settle the horses. A young goat. An idiom is a turn of phrase that doesn't make sense when literally translated.
Description: GTF file is a General Feature Format File. The Gene transfer format (GTF) is a file format used to hold information about gene structure. It is a tab-delimited text format based on the general feature format (GFF), but contains some additional conventions specific to gene information.
GIF files are image files that can be created by a number of different graphics applications. Files with the .gif file extension can contain up to 256 colors. GIF files are often used in web graphics and are commonly used to create graphic text for websites. While the pixels in a GIF file can be transparent, they must either be fully transparent or fully opaque when creating or editing the image. They cannot be alpha-blended, like with e.g. PNG images.