Also sometimes called Apps. Apps is short for “applications,” as in, an application (or piece of software) that can perform a particular function (such as organizing photos or quickly ordering a pizza on your phone.) An app is generally dependent on a larger piece of software that has a larger (but less humanly interactive) functionality.
I find it easiest to think in terms of solar systems. You take a big piece of software and put it in the middle. This is your basic workhorse: your sun. Then, for additional needs, you add other smaller programs with more limited functionality: planets. For instance, your phone contains an operating system which keeps everything in line, but with which you don’t really interact. A few apps are preinstalled, for basic tasks like storing contacts, texting, etc. Then, you go to your app store to get smaller applications to perform particular jobs. You might download a game, or a link to some business software that is stored in the cloud, or a link to your home security system so that you can check to make sure all the lights were turned out.
Depending on what you are doing, you may find one browser better suited to your needs. Once you settle on the purpose of your computing, read about it to make sure you are using a compatible browser, and that the apps you want are also compatible. There’s nothing worse than rushing through the process and finding incompatibilities between apps. This is getting better, but it is by no means perfect.
The first big choice for pretty much all software these days is, desktop or cloud. How do you intend to work? Do you do everything in an office? Or might you need to do some tasks on the run? Do you have a diligent bookkeeper chained to a nearby chair, or are you outsourcing the grunt work? Do you have sales staff that needs to stay connected on the go? Do you have an internal IT department? Do you have enough bandwidth to let everyone visit the cloud at once?
If you are not sure, or you just want to make sure you have it right, stop right now and talk to your accountant. If you have an experienced, competent bookkeeper, you might let the bookkeeper decide. Then again, you may just snuggle up to a coordinated set of apps that work better in the cloud than on the desktop (not an unusual position these days) and your choice will be made for you. But please check first! And don’t let the salesman in the big box office supply store tell you what to do or buy.