Snow Leopard needs to be purchased on a disc it can then be installed to update Mac OS X 10.5.8
The software version available after the leopard version is something called 'Snow Leopard'.
10.5, Snow Leopard is 10.6
Mac "Lion" and Mac "Snow Leopard" refer to iterations of Apple's Mac OS X (operating system, version 10). "Lion" is the newest as of this writing, and is version 10.7, while "Snow Leopard" is its immediate predecessor, and is version 10.6.
The Mac's operating system is called Mac OS X. Each version of Mac OS X is named after a big cat. The current version (number 10.6) is called Snow Leopard; the previous version (10.5) was Leopard and the next version (10.7) will be Lion.
Each version of Apple's operating system for their computers, Mac OS X, is named after a member of the cat family, Tiger, Panther, Leopard etc. The current version, Mac OS X 10.6, is known as Snow Leopard.
Mac OS X 10.6 (Snow Leopard) is only legally available to buy from a software retailer.
Go to the apple icon in the upper left hand corner of your desktop... Select "About this Mac" if the software version is 10.6 or later, you have snow leopard.
a snow leopard is the lightest leopard
All new Macs are supplied with the latest version of Mac OS X which is currently 10.6 Snow Leopard.
If your current version of Mac OS X is 10.4 (Tiger) or 10.5 (Leopard) then it will cost around $29 (£26) to buy the update to 10.6 (Snow Leopard). Snow Leopard only works on Macs with an Intel processor and will not work on older G4 and G5 Macs which can only upgrade as far as Leopard.
You have Leopard which is (10.5.8). One of the requirements for installing Lion is that you already have Snow Leopard (OSx 10.6) or later installed. The main reason is that Lion is available only via the Mac App Store, and the Mac App Store debuted in Mac OSx Snow Leopard (10.6.6). In other words, you need Snow Leopard just to purchase and download Lion. So you are going to have to purchase and install Snow Leopard before you can proceed to purchase and install Lion. If you bought your Mac at a retail store then go back and ask them for a free updrade to Snow Leopard. They may just give it to you for free if you agree to purchase Lion which should cost you around $20. Does not hurt to ask. If you purchased it online then contact Apple for the upgrade to Snow Leopard.
A snow leopard is a preditor