Suppose you buy a new device. You must connect it to the computer either with power ON or power OFF. Each device has a different power supply need and will be recognized only if connected in the proper format. Let us look at few devices and how we need to connect them.
Many of the removable storage devices are hot swappable. This means that you can insert and remove the device with the system powered on. Most USB-attached devices without a file system fall into this category. On the other hand, non-hot-swappable devices either cannot have the system's power applied when inserting or removing them or they have some sort of additional conditions for their insertion or removal.
One subset is occasionally referred to as cold-swappable, the other as warm swappable. Cold-swappable devices must have the system power off before you can insert or remove them. An example of a cold-swappable device is anything connected to the PS/2-stylemini- DIN connector, such as a keyboard or mouse. Insertion with the power ON generally results in lack of recognition for the device and might damage the motherboard. AT keyboards and the full-sized DIN connector have the same restriction.
Warm-swappable devices include USB thumb drives and external drives that have a file system.Windows and other operating systems tend to leave files open while accessing them and write cached changes to them at a later time, based on the algorithm is use by the software. Removing such a device without using Safely Remove Hardware utility can result in data loss. However, after stopping the device with the utility, you can remove it without powering down the system, hence the “warm” component of the category's name.
If you would like to learn more about hardware and how they can be connected or disconnected, you can join a course for a CompTIA A+ certification. Institutes such as SLA IT Employment Training Company offer instructor-led courses in A+. For more details, visit SLA A+ Certification in Chennai or dial (91 44) 4200 5050/90.