Oracle Linux is free and you can install it to run your business. Also updates and patches are freely available.
Other info about available payed support subscriptions (ULN) and more can be found in he FAQ and whitepapers:
and certainly here:
Oracle Linux is available for free. But without support and without patches.
Please see the first link to the Oracle press release from March last year of my previous response:
Effective immediately, Oracle will provide its Red Hat compatible Linux binaries, updates and errata for free http://public-yum.oracle.com. Terms, conditions and restrictions apply.
So everyone can update the system to the latest patch levels without a support subscription, including the Oracle UEK kernel. Also some userspace software that is not GPL, e.g. oracleasmlib is available for free. But UEK kernel features like Dtrace and Ksplice require a support subscription and access to ULN.
Are you asking about your OS licensing (Linux itself) or are you asking about the licensing for the database and apps? If you're asking about Linux, others have already answered.
If you're asking about the database/apps licensing, Oracle will transfer your existing licenses (which could answer whether you get processor or named user licensing) but they calculate the license requirements differently for different processors so it's possibly not going to be a straight 1-for-1 swap.
Have a read through the licensing documents for each of the products you have to get an idea what you're looking at - then I'd advise that you speak to your account manager at Oracle. I've found them to be very helpful in the past and it's better to get it "straight from the horses mouth" than guess and then find out during an audit in a few years that you've been paying for licenses you don't need.. or worse, that you've been running without enough licenses.
Hope that helps.