Graphics also help to make a website special. And there are a number of things to consider as you decide what graphics to use.

First of all, you don't want to overuse them. Use just what you need to show people what the website is about. If you are an artist or craftsperson, then you would want pictures of your work so that people could see what you do. If you are a business, then you may want to show your product or pictures that show your service in action. In this case, you may want to focus more on the text side of the website.

Something else to think about is who your customers are most likely to be. I know a number of my clients have customers that live in the country and so are more likely to be on a dial-up internet service rather than high-speed service. In that case you need to go as light as you can on the graphics because they take up considerably more file space than text does, and as a result take a lot longer to upload on the dial-up systems.

What I also do to help with that is to resize any graphics down to the smallest size that I use them as on the website. And just in case your webdesigner happens to talk about image sizes, that will most likely be in pixels (which are dots per inch). Just as a rough estimate, there are approximately 100 pixels per inch when you are talking about website graphics.

If you are going to have graphics on your website, you will need to be able to send those to your webdesigner in digital format by e-mail. Or provide them on a CD. If you bring paper photographs that the webdesigner has to scan in, be prepared to pay for the extra time and effort involved in that. If your graphics need to be altered or resized or otherwise changed, there can often be a fee associated with that as well. As with any other graphics that the webdesigner creates for you.

On websites today it is possible to put in graphics that move and change and do all kinds of wonderful things. I haven't gotten into that, partly because the more I learned about websites and the more I spent time on websites, the more I realized that there really isn't a lot of need for movement on a website. If you are showing videos to highlight something, that's okay. But even that only moves when you click on Play.   This is an example of moving text that comes in and stops. 
Other than that, moving graphics - like text, etc that moves or changes color or flashes at you - often end up being more distracting than helpful. There have been a few times when I have added very short segments of moving text (See sample just above.) to draw attention to something right up front, but only as a one-time movement.   Compare that to this one which goes faster and keeps repeating over and over again.  
Constantly repeating text or graphics (See second sample, just above.) soon have you feeling annoyed if not seasick. It becomes very difficult to concentrate on reading something when that movement keeps distracting you.
And by the way, if you use something other than Internet Explorer, you may not be able to see the above samples in action.)

If there is a good reason why you would want movement on your website, that is something you would need to discuss with your webdesigner.