QuickStego lets you hide text in pictures so that only other users of QuickStego can retrieve and read the hidden secret messages. Once text is hidden in an image the saved picture is still a 'picture', it will load just like any other image and appear as it did before. The image can be saved, emailed, uploaded to the web (see the picture of the lady with a laptop above - this image has hidden text) as before, the only difference will be that it contains hidden text.
The larger the image, the more text that can be concealed within. QuickStego will tell you how many characters of text you must lose if you go over this limit per picture. In practice a lot of secret text can be hidden in even a small image.
QuickStego imperceptibly alters the pixels (individual picture elements) of the image, encoding the secret text by adding small variations in color to the image. In practice, to the human eye, these small differences do not appear to change the image.