Music recording software is a special application that turns a computer into a music recording machine. This is not some prohibitively expensive software that runs on giant workstations. Typical music recording software runs on ordinary computer and usually costs less than audio hardware needed to interface computer with music sources. Of course, in most cases you will use a dedicated computer which will be modified for low noise operation. Some recording software also requires dedicated hardware (e.g. Pro Tools) but this only means that the music recording quality will be high as it is expected for any professional recording studio.
Before you make a decision for a music recording software you will purchase for your recording studio you should have a clear vision of what do you need and which features are mandatory. Most recording software will run on your home computer and will work with the built-in sound card. This way you can test a demo version before you spend some money for a dedicated recording hardware. Every music recording software supports basic functions like recording, editing and playback. But here similarities end. Each software offers many additional functions that make it better than the competition. Multi-track recording, mastering, special effects, audio "cleaning", and other features is what you should compare and test.
Portability is also one of the required features if you intend to transfer recordings from one studio to another. You can always transfer audio in one of the standard formats, but this is not what you can do in the middle of the project. If you intend to cooperate with some studios you should check what recording software they are using and try to go for the same or at least compatible software on some level. Each recording software has a specific user interface. Some mimic real recording equipment, while others have invented unique approaches and designs. Make sure you are comfortable with the software, when you record music you should be focused on instruments, levels, balance and not on mouse, keyboard or shortcuts.
In some cases you will purchase software for existing studio equipment and computer. But in most cases it is best to go for compatible and balanced hardware and software. Music recording software is only one link in the chain, make sure there are no weak links. Some prefer PCs and others work only with Macs. There is no significant difference, most recording applications support both platforms. But to be sure you should check what is the primary platform and what are the recommendations. And finally, remember, every software is a complex system. Don't expect that you will master it in a few days. Take some time, read manual, experiment, listen your recording in a different environment, pay attention to details, repeat recording with different settings and be patient. The beauty of computers and software is that you can repeat steps until you are satisfied. The most common operation in the world of computers is Undo.