I have some problem with my browsers Chrome and Firefox. Sometimes my websites hosted on godaddy do not open, but after 10 or 15 minutes the sites will open again. This issue is with my sites only. I even deleted the cache but still the issue is not resolved. What could be the reason for this ?
Try monitoring your website with a downtime monitoring software to know when it goes down. Pingdom.com is a popular option (cheaper alternatives exist).
Technically, if you host a website that is heavier for the hosting space you bought, you website will go down from time to time (since it is on shared resources and when other website on same space uses more processing, yours goes down)