It is an old concept in branding; it was always recommended to stick using one word for your brand because simplicity can be the key to having your brand name become widely recognized.
Domain names are just another form of branding. Of course you can use two words, but this might cause unnecessary confusion on the customer part – like whether or not they should add a hyphen to your web address or not, e.g. is it http://www.JordanSoft.com or http://www.Jordan-Soft.com?
Is it better for search engines? It depends on the keywords you are targeting; sometimes two words might bring you more traffic. Domains longer than 4 words are considered a spam and might not be accepted well by search engines, it is recommended to keep your domain short.