Regardless of distro, a package is usually a file containing an archive of files needed to install some library, programme or driver. Sometime a package simply gives links to a variety of other packages to permit installing them together. Often, it contains a script that carries out configuration steps automatically. The package manager checks the versions and dependencies so that all should go smoothly. If you need to know how to use the result of an installation, one can read the documentations contained in the package or from another source, like the homepage of the open source project that may have created the package.
Your profile does not specify your distro, but assuming it is based on RPM, rpm -q --info -p packagefile or rpm -q --filesbypkg -p packagefile may be useful. rpm -Uvh packagefile installs the rpm.
A driver is a part of the kernel and is usually installed as a loadable kernel module which may need to be loaded via the modprobe command. lsmod may show the currently loaded modules. The script accompanying the package may load the driver automatically or prepare your system to load the module at boot time.