secure tunnel client question

I just recently found out that I need a secure tunnel client in order to access an API, OK. Then while researching I find way too much conflicting info about what it is exactly. Could someone shed some light? Is it a subscription? Does it live in my PC or on a server? Why do I need it if I have a SSL via https?

Secure Shell or SSH is a network protocol that allows data to be exchanged using a secure channel between two networked devices. Used primarily on Linux and Unix based systems to access shell accounts, SSH was designed as a replacement for TELNET and other insecure remote shells, which sent information, notably passwords, in plaintext, leaving them open to interception. The encryption used by SSH provides confidentiality and integrity of data over an insecure network, such as the Internet. For additional information see http://en.wikipedia.org/wiki/Secure_Shell

If you do not already have one on your home system pick download and install an SSH Client. Most people use PuTTY. PuTTY can be download from the link below:
http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html

I use putty as my ssh client on windows and have my login for my Linux Web server set up to tunnel port 3306 for mysql. As far as the server is concerned I am connected locally to port 3306 and on my windows system I am also connected to the local port 3306.

To set this up you need to start p[utty and get to the Putty Configuration screen. Next click the plus sign next SSH under the lowest sub heading Connection. When the next sub menu opens select Tunnels from the list under SSH. For the next part we select a port on your local system that you want to be forwarded. Put this in the box marked source port(for mysql you would use 3306). Put localhost:3306 in the Destination box and click add.

To use the tunnel you must first login to the server via ssh and then the tunnel will be active.

Hopefully this has made sense if not email me and I will forward a work document I put together on it with screen shots