It's worth familiarising yourself with the built in functions of your user control panel.
The image below is a typical control panel, and has clickable 'hotspots' that will give you information about that topic.

control panel colour scheme may vary from that shown

Password Protection:
A password protected directory will only allow anyone who knows the password to access files stored in the protected directory.
Before access is granted to the protected directory, a dialog box will 'pop up' and the person trying to access the directory will need to enter

The protection mechanism used is a 'simple' .htaccess file is written into the directory concerned.
Don't let the 'simple' bit fool you into thinking that gaining access to the directory would be easy... This type of protection is much stronger than many alternatives.

The downside is that you can only have a single  , which is fine for just yourself or small groups, but for larger groups you may need to consider a 'multi user' password protection system.

We do have such a system available, and it can be installed for a one off payment of £40.00