Apple calls it a "Video out port" in most all of their documentation I found (owners manual, etc.). They refer to it as a mini-VGA with the cables that attach to this port. They can really call it whatever they want since it is a proprietary Apple only video port.
Here is a link for adapter to s-video and composite
Here is a link for adapter to VGA
Now to your problem, Phillips has not made this TV computer compatible. Manufacturers that are will include a VGA or DVI port. This one does not. You have s-video, component and HDMI ports only. There are cables and boxes that will take VGA and audio, convert the analog signal and push it down an HDMI cable. Most of these will run you $150 - $200 (and you don't have the HDMI cable with that) and are available only at specialty cable shops online. Have never seen anything like this in a local store of any kind.
2nd option in this portion is to go VGA to component. Once again, you are looking at high dollar costs just to get your iMac to the TV at 720p instead of 480p, and from my experience will not be worth the cost for most.
Here is one box that will do this for you. If you want to look for others, just put "vga to component" or "vga to hdmi" into google.
So your best bet is going to be getting the cable in the first link above and then using an s-video cable. Not the best picture, but it will get you to 480p on the TV. If the TV has good processing internally you will get a decent picture for viewing movies, pictures, etc. from your computer. You will probably not want to use it for viewing text documents nor browsing the web.
Have not touched on audio, if you need help there, give a post back.