Nope. Not a Photoshop specific thing. I use Paint Shop Pro.

Resampling is basically rescaling the pixels instead of  just shrinking them down. By choosing the right Resampling option you can often eliminate or reduce the amount of image quality loss IE:  a crisp image becoming blurry or pixelated after reducing its size.  In Paint Shop Pro (probably other graphic programs too), you can choose from:

• Bicubic: Best used to enlarge a realistic or complex image or to avoid jagged edges.

• Bilinear: Best used to reduce images that have well defined edges or text.

• Pixel: Best used for drawn images or ones with well defined edges.

• Weighted: Best used if the Bilinear option doesn't work.

• Smart Size: Lets Paintshop Pro decide how to resize the image. Usually requires the image to be "sharpened" after size reduction.

NOTE: Bicubic and Bilinear resampling options can only be used on images that are 24 bit (16 million colours) and grey scale images. You can still use these on the image, but you will have to increase the colour depth of the image first by going to Image Menu --> Increase Colour Depth --> 16 million colours. Once you have resized the image you can go back to the Image Menu --> Decrease Colour Depth, and choose which option you want to use.

While each option has it's purpose, none of them will work 100% of the time. Sometimes "Smart Size" and then "Sharpening" the image works best. Other times "Bicubic" will. I find for my purposes when creating a tutorial, that I prefer to use "Smart Size" and then "Sharpen" the image afterward otherwise the text becomes unreadable and grainy. But when I'm resizing textures, I use Bicubic Resampling to prevent the pixels from blurring.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi