What do we mean by a 'Flash Site'.
A Flash File is similar to a power point presentation. The difference is that it can be displayed or embedded on a web page. Small Flash files are sometimes used at the top of a web page to display advertising. Sometimes they are used to present a picture gallery slide show.
It is also possible to create an entire web site with Flash.
The disadvantages are several. First some visitors might not have the software to display the page correctly. In this case you may have a customer who will simply not be able to see your site. Secondly the flash files are quite large. If a customer has dial up then it might take forever to download. In this case your customer or potential customer might give up and go to your competitor's site. The third obstacle is that Flash is not HTML. The search engines can not read these files. Therefore you might have a challenge getting indexed on the search engines.
That being said, Flash Sites are very cool. They seem to be used by trendy businesses. If all of your customers are under 30, play video games, and have no attention span, then a Flash Site might be just the ticket. For most businesses I would not suggest a Flash Site.
On each web page a flash file is embedded that generally takes up the full browser screen. Then active scripting is used so that a click on the navigation bar brings the visitor to the next page. Because the size of the file is fixed to the browser window it is difficult to display long pages. Often there are scroll bars in the middle of the screen to allow the visitor to view the entire content.
The effects you can achieve with Flash are limitless. Graphics and text can move around, disappear, zoom in, fade out. Pictures can overlap each other and be merged with varying opacity. All of this is very cool.
If your heart is set on having a Flash site, you should consider modifying an existing template. A template can be purchased for $100 or so. Then your web designer will simply change the content to match your business. This is the most affordable option and could be done for less than $1,000.