I just got answare on my mail from offensive-security.com and they said OSCP does not expire.

Can someone tell me what this mean:Offensive Security Live courses qualify you for ISC2 CPE Credits?
Im totaly new to this world of ethical hacking so sorry if i ask stupid question  

I was planing to take this cours in future so i wana know one think.
How long is this certificat valid,is it limited on some time so i need to do it again after maybe 2-3 year or i do it once and its stay valid always?