Software is something that allows PCs to complete a specific task, it comes in many different forms as we'll discuss in more detail later. For example, system software is something that we all use everyday - such as the operating system, the thing we use to complete all of our tasks. There are multiple different OS's that are used in computing these days, with the most popular one being Windows. You'll probably be more familiar with application software, which is more specific in your needs and attempts to complete smaller tasks by using the system as a resource.
There are three main types of software, two of which we've already mentioned - application software, system software and programming software. The programming type is something that developers can use to aid them in creating their own apps (although this is the most uncommon type). Before something can be used, it has to be loaded onto the hard drive or a portable media device which you probably already know by now. When this is done, it can use the processor to execute commands as desired.
When it comes to system software you don't have a great deal of choice about what you use. Most of them are built into the computer and won't need to be changed by you which is exactly as it should be for the end user. The process needs to be as simple as possible. The main OS's you can select from are Windows (the market leader), Linux (a free open source alternative that is used to power a lot of electrical devices) and Mac OS X (paid and requires a Mac computer too). In each of these there is a lot of work that is done in the background that you probably won't even realise is going on, all to ensure that your system runs efficiently and smoothly.
Something that you're probably more interested in is application software, the stuff you use everyday. Mac OS X Mountain Lion was released recently which provides extras such as a Reminders app and Notes app, making the divide between Mac OS X and iOS much smaller. There are of course much more than have been developed by other companies and can be downloaded online. This can be done through the Mac App Store or through software download sites you can find through search engines. Click here for an example of one.
Mac apps are generally much safer than Windows software but you should still be careful when downloading something from the internet. Checking reviews and using antivirus tools is a good way of checking that the things you're downloaded are genuinely what you want. Probably the most difficult part of the process is selecting the ones you want especially due to the great number of programs that have been released to do the same job. By checking out sites like the one we've provided, you're able to get a much better idea about what would be best for you to use and what the features of them are.