I have two machines:
In the first machine I installed:
I connect to local/remote oracle databases without problem.
The second machine is a fresh server installation, it does not have local oracle dabatases, nothing. The idea is to connect to a remote oracle instace. So I made the same installation (apache and php with same versions as first machine), but the first error I found was that the oci8_11g extension is not loaded. My question is, do I need to install some "driver" or "client" for oracle in this server? The apache instance and php work as expected except with error mentioned.
You are using windows, right? In that case, you need to install Oracle Driver (http://www.oracle.com/technetwork/topics/winx64soft-089540.html). "Basic" package should do.
Also uncomment this line from php.ini: extension=php_oci8.dll, or extension=php_oci811g.dll, or extension=php_oci812c.dll, depending on which oracle version you are using.