Notes:

Lossy vs. lossless image file formats

For better utilization of storage space, utilizing the bandwidth efficiently over the internet and for more other reasons images are going to be compressed and decompressed several times.

When we compress an image some of the data is going to be removed from the image, hence automatically image size reduces on compression. To get back the original image, on decompression the removed data is going to be added back to compressed image. That means once we compress an image, we can reconstruct the original image from compressed image.

There are two types of compression algorithms, which perform these tasks.

Lossless compression algorithms:
Allow the original image to be exactly reconstructed from the compressed image.
No loss of data.
No loss of quality.
Lossless image file formats:
PNG, GIF, TIFF, TGA

Lossy compression algorithms:
Allow the original image to be approximately reconstructed from the compressed image.
Loss of data.
Loss of quality.
Lossy image file formats:
BMP, JPEG

Full form of various image file formats
Vector Image files formats:
.ai (Adobe Illustrator)
.cdr (Corel Draw)
.svg (Scalable Vector Graphics)
.swf (Shock Wave Flash)

Raster Image files formats:
.bmp (Bit Map Picture)
.jpeg (Joint Photographic Experts Group)
.png (Portable Network Graphics)
.gif (Graphics Interchange Format)
.tga (Targa)
.tiff (Tagged Image File Format)