turn:
This machine is installed oracle, this machine also need to install the client do?
This machine is installed oracle, this machine also need to install the client do?
answer:
No installation, because when you install the oracle, the default installation of the client. So, sqlplus you this machine can be used, sqlplus is the client.
Unless the situation:
You need to use plsql, while you are installing a 64-bit oracle, it would need to install a separate 32-bit client oracle, plsql can not be identified because the 64-bit clients (mainly oci.dll file. After installing oracle and oracle client is not installed, in fact, already oci.dll installation, product in the oracle installation directory \ 11.2.0 \ dbhome_1 \ BIN down).
Normally this reason it is installed oracle client is installed in order to use the plsql.
Above that is the machine , if other machines need to access oracle me this machine must be installed oracle client, simple installation plsql is simply useless.