What is the best image format for our web site if we needed our image to have a transparent background?
a. jpfg
b. jpg
c. gif
d. png
e. psd
f. tiff

PNG

Explanation:

Convertible or not :

First of all you should know that you can't make a JPEG image transparent. You should use a format that allows transparency, like GIF or PNG TIFF.

PNG VS GIF VS TIFF :

When we talk about which one to use there are two things that comes in mind.

1. Flexibility :

JPGhas Millions of colors to use. it is used for Still Images  Photography

GIF has Maximum 256 colors and is used for Simple animations

, Graphics with flat colors  Graphics without gradients

PNG-8 has Maximum 256 colorsused for Similar to GIF  with Better transparency but no animation  and known Great for icons

PNG-24 has Unlimited colors Similar to PNG-8  Handles still images and transparency

SVG has Vector with Unlimited colors Graphics/logos for web

Retina/high-dpi screens

2. Size

Size depends on the colors you will use.