[MUSIC] Hi. As you saw during the first week, most of the information we exchange today is not saved nor transmitted using analog supports. Information is stored in data supports like drives inside of computers or smartphones, portable USB drives that we carry around, or even servers in the cloud. In information security and other computer science related fields, we consider three different states for data information or data. Data at rest, data in use, and data in motion. Data at rest refers to all information that is being stored but not used in a data support. This includes information in hard drives inside of personal computers or servers. Portable USB Drives that we use transfer data between computers. The so called Flash Memory that we used or detail cameras or smartphones or DVDs and Blu-ray discs. Data in motion refers to the information that is been transmitted between devices over a network, this includes or credentials when we authenticate to access a remote service, a web page request from a web server, a live streaming video, or a message you just sent using the Send button on your instant messaging application. Finally, data in use refers to information that is being actively used by an information system or computer. Data in use is generated at run time, read from persistent storage, or received from the network. Unless generated at run time, data addressed or in motion, is transferred to the short term memory of the device to be used. We generally call this kind of memory random access memory, or directly RAM. These memories are volatile. Meaning, that information stored on them gets lost quickly if they stop receiving electricity. Examples on information in use can be taken from all the application who generally to edit an access content from our devices. A Word document being edited at a sign or even the text type on a messaging app. Furthermore get to applications who used to access those documents are also data in use as they are read from persistent storage and loaded into memory to be executed. In the penalty of its step, information is always subject to threats. Information can be eavesdropped when it has been sent over wireless network, thieves can steal devices, also the criminals can try to read your data without your consent. During this week, we will review how is it that security of information in each of its states can be compromised, and what can we do to mitigate these risks. At the end of this week, you should be able to enumerate the different threats that affect computers and their networks. Be aware of the risks of the risks that exist when information is transmitted through a network. Relate the security protocols included in the existing network technologies. Define and differentiate the terms, authentication and authorization. And leaves the kind of vulnerabilities that may affect a computer system. [MUSIC]