Fixing permissions is recommended before and after installing any software to your mac as well as installing any software updates. There are various software available on the Internet to help you keep your Mac maintained and in a “good health”. Software such as Onyx or Cocktail are doing a great job by not only repairing and verifying permissions for you but also cleaning the internet history,cache,temporary files and running optimization scripts.

If you for some reason are unable to boot your system,before you do anything like re-installing the OS, try pressing command + S on the system boot-up and it will get you into console mode. Type in /sbin/fsck -fy and hit enter. Do that couple of times until it doesn’t say “System Modified”. Before you use “fsck” command, I advise you to open terminal, type in man fsck and read the manual page carefully. Not all software errors are as easy to fix by using methods above. Some errors and system misbehaving can indicate serious hardware failure so if the problems persist, the best is to take your mac to an authorized Apple service for a check-up.

What is computer hardware?
All those components of computer system that are tangible and on which either input could be given (like keyboard and mouse etc.) or output could be received (like monitor and printer etc.) are known as computer hardware. These hardware components of computer system themselves do not generate instructions but process the instructions generated by either software or user.

Computer hardware is only a subset of word hardware that is when we say computer hardware we only mean the hardware used in computer system but if we say only hardware we mean all the hardware that can be used in any machine. Computer hardware includes following parts in computer system like: keyboard, mouse, floppy drive, hard disk, CD Drive, printer, RAM etc.
But do the hardware alone makes the computer system not it is wrong. A computer system with hardware and without software is life less that means it is same as like a skeleton without life. To make a computer system fully functional software is essential with the hardware. The very basic software that is required for making computer to work in a friendly manner and making it to support all the user activities is operating system.

What is Operating System?
In a layman language operating system is the software that brings life to computer system. Operating system itself does not do any thing but provides an environment in which other software programs could execute. It provides an interface between the user and the computer hardware. It directs the user to operate on the computer. It provides guidelines to user on how to work on computer. Operating system is the software that makes other hardware work in an efficient manner.

The field of hardware and software has also become the career for new generation and has very wide prospects in this field. People who wanted them to be established as hardware or software engineers can complete their degree or diploma course from any reputed institution and start their career with the established organization or can if they are willing to be entrepreneurs they can start their own company working in this field.