Using ckeditor in a website: License

Hi,

I'm fairly new to ckeditor and I'm wondering (reading all the licenses takes too much time) if I can use ckeditor inside a website I make for a company. CKeditor will only be used on this website and not being selled itself. This website is not opensource (preventing security issues). Do I have to buy the license or can I use it on this website?

Thanks in advance,
Stijn.