Pass your certification exam. Faster. Guaranteed.

Computer Components Transcription

Welcome to our Security Capabilities of Information Systems Computer Architecture Model. It is important to be familiar with the parts of the computer system that make it operate. The processor, or central processing unit, is like the brain of the computer, and is responsible for processing tasks. Memory, known as RAM or random access memory is a volatile storage area that is used for temporary storage while using programs and applications.

Volatile means that it needs to be powered on in order to retain its memory. So as soon as you turn off the computer, you will lose whatever is stored in the memory or RAM. Your storage device could be either a hard drive or a solid state drive. And this is an area of non-volatile storage, meaning that it can retain its memory, even when the power is off.

This is where users store their applications and data. There are buses inside the computer that carry data and power between multiple components. Most computers have some type of networking connection to allow it to communicate with other devices. This could be a hardwired connection such as an Ethernet connection, or it could be a wireless connection such as WiFi.

Your computer will also have software which allows it perform different functions. All computers have an operating system, which is the basic software that runs the system. And then users install applications on top of the operating system to perform their necessary functions, such as word processing or browsing the internet.

In order for your system to function properly and to remain secure, all of these complex components have to work correctly together. And you must control the interaction between the components. Read only memory, as the name implies, can only be read from and cannot be written to. The contents of this storage area are burned in at the factory, and this is not an area where users store data.

A PROM, or programmable read-only memory, contains an area where information can be burned in by the end-user, but then cannot be modified after the fact. EPROM, or erasable programmable read-only memory, contains contents that can only be erased by exposing the device to a strong ultraviolet light, and then re-programming the contents.

An EEPROM, or electronically erasable programmable read-only memory, can be erase with a electrical charge and then rewritten and therefore can be written without removing the chip from the computer. Flash memory is a newer form of EEPROM that can be erased and rewritten in blocks. Computers can have several different applications running at one time which means that many processes could be running at once. Processes are made up of threads of computer code and each process can handle something different. In this example we can see that there are three processes or applications running. The first process has three threads, one of which is sending data to the computer's monitor. The second process has two threads, one of which is printing a document.

And the third application has two threads, one of which is saving data to the disk. When a process first starts, it is in the new state and then it moves to the ready state. If the CPU is available, the process will move directly to the running state. But if the CPU is not available, the process will wait until the CPU is available, and then will run.

Once the process is finished running, then it will be terminated. We can have two different types of computer systems, open or closed. Open systems are built on published standards, interfaces and protocols, and are designed to easily integrate with other systems. However, these open systems are typically more vulnerable to attacks because they use generic system components.

Closed systems are designed only to work with a very specific range of other systems. This is very common with mobile devices, the example being Apple's iOS software which only runs on very specific hardware. Which allows the manufacturer to optimize the software for that specific hardware. In order to attack a closed system, an attacker would need to have much more in depth knowledge about how the system works.

This should not be confused with open source versus closed source software. Open source software allows the source code to be made available to the general public, so that others can peer review the software and the developers can work together in a community. Closed source software does not allow their source code to be given out to the public.

However, the source code can still be revealed through unauthorized disclosure or decompiling of the source code. Typically, with closed software, updates are scheduled, and you can only install updates once the developer decides to release them to you. This concludes our security capabilities of information systems module. Thank you for watching.