there is no such difference in personal use and commerical use the only diff I think is of the content of the website ... it you are using some other people content on your website for commercial use then you have to pay loyality
It really depends on the details of the license, and what is being licensed. If you are talking about development software, then a personal use license is usually good for anything you create for yourself and yourself only (not for your partnership or even for "You, Incorporated"), whether the site makes money or not. You would not be allowed to use the software to create anything for anybody else, so advertising yourself online as a web developer while holding a "personal use" license for the software you use might not be a good idea.
If you are talking about images, fonts or other media, then a "personal use" license would strictly forbid any commercial gain. It's not the designer/developer that matters in that case, it's the context in which the media are used. You can usually use the media on a site that you have developed for somebody else, provided that there are no explicit restrictions stating otherwise. In this case, the "use" is the web impression, so if the web page the media appears on is non-commercial, and you have explicitly omitted the images used from any design/development contract, you may be able to include the media in a design you've done for a client (but it's always best to check with the artist or copyright holder if you can, as a courtesy if for nothing else).
I think, commercial use in general, is where a user uses his/her website to earn money by selling tangible and/or intangible things such as software, books, services, etc. As long as the website is intended for business purposes, then it is commercial. While personal use refer to personal usage only, such as personal blogs, online resume, etc. I don't think placing ads on a personal website automatically makes the website a commercial one. Although you earn money from it, what you are actually doing is simply rent a portion of a space of your webpage to a paying advertiser. But if the primary purpose of your website is to display ads, then I think it will be considered as a commercial website. Analogy: supposing an advertiser wants to stick a poster of their products to the wall of your house and pay you in return, that doesn't make your house a business establishment. But if an advertiser wants to advertise through your large billboard and pay you in return, then that would make your billboard a commercial entity.
Yes, I think shys_aelaes26 is correct. If you use something 'commerically' then it means you are profiting from it, while 'personal' is for your own use.
As an example, let's take a wallpaper that someone made.
If I was to use this wallpaper as my desktop, that would be Personal.
If I was to sell this wallpaper (but the author probably wouldn't let me) that would be Commercial.
From my point of view, personal use is something that only you, your family membors, or your friends is using. Commercial is something that you used like in school, or in a business to make money. I think the use in small businesses/schools counts as personal use too.