Images.
picture file.
.jpg is a picture format.
Image file
* matches anything. *.jpg would mean any file with a .jpg extension. 1*.jpg would mean any file where the name begins with 1 and ends with a .jpg ? matches any single character. ?.jpg would match a.jpg, 1.jpg, or F.jpg but not a1.jpg. Several ? wildcards can be used so that ??.jpg would match any jpg file with a two letter name.
yes
There is only one file that the name ends with GIF. The only file that ends with GIF is saving a picture.
an image file
picture file.
Just change the extension (Rename).There is no difference between jpg and jpeg as file types ot kind of information they contain.
It depends on your file system. Some filesystems are CASE sensitive but typically JPG and jpg are the same thing.
.jpg
you should use software coverter jpg to pdf, you can search with keyword jpg to pdf on google