A network or network infrastructure is the grouping of hardware devices and software components needed to connect devices within an organization and to connect the organization to other organizations and the Internet. The network infrastructure’s physical hardware and logical components are needed to provide a number of features for the network, including connectivity, routing and switching capabilities, network security, and access control. The network or network infrastructure has to exist before a number of servers needed to support applications that users need can be deployed into a networking environment. Therefore, Read More

Hydronic air handlers have become a popular installation for home owners who build a new home or are replacing the HVAC system in an existing one. A hydronic air handler is significantly more fuel efficient, runs quieter, and produces more comfortable heating than a traditional furnace. It does this by providing uniformly heated air, thereby avoiding the hot, nasty blasts of hot air experienced with traditional heating systems. How Does a Hydronic Air Handler Work? To heat air, a hydronic water heater uses either a hot water heater or boiler Read More

Merging means combining elements of two arrays to form a new array. The simplest way of merging two arrays is to first copy all the elements of one array into a new array and then append all the elements of the second array to the new array. If you want the resultant array to be sorted, you can sort it by any of the sorting techniques. If the arrays are originally in sorted order, they can be merged in such a way as to ensure that the combined array is Read More

The term port knocking refers to a type of host-to-host communication where the information flows across closed ports. The primary purpose of port knocking is to keep attackers from successfully conducting a port scan since the server will require the correct port knocking protocol or sequence before the port is opened. There are a few types of port knocking methods, including encoding information in a packet-payload or a port sequence. When the port knocking method is used, the data is sent to a closed port and a daemon that is Read More

A charge-coupled device (CCD) is a two-dimensional grid of semiconductor capacitors that can transfer charge between each other. While the term is widely used for image sensors, it actually describes the process by which the charges are transferred through the capacitors towards the grid edge. CCD History The concept of digital photography was first developed in 1961 at the Jet Propulsion Laboratory, but it wasn't until 1969 that the first CCD was invented at Bell Labs. Commercial CCDs started appearing during the early 1970s, and one of the first uses Read More

Afd.sys (Windows Ancillary Function Driver) is a driver for Winsock, which is a program necessary to connect the computer to the Internet. It runs when the computer is booted and is responsible for all Internet connections on the computer, including wireless, LAN, browser, and third-party application connections. Afd.sys is a critical part of the Windows Operating System and should not be removed under any circumstances. Afd.sys can be found in the Drivers subfolder of the System32 folder on the primary hard drive.   How Afd.sys Works Afd.sys is a driver Read More

A macro is a template of commands and functions which can be used to facilitate automation of tasks you repeatedly do in Microsoft Excel. You can specify if a macro is available only to a certain workbook or to all Microsoft Excel files. Set the Security Level to Medium or Low Open an Microsoft Excel workbook or create a new one. Prior to creating and recording a macro through Excel, set your computer’s security level to medium or low so you can run macros in Excel. To do this, click Read More

iTunes is the digital media player that Apple produced to organize and play digital music and video files. It is also an interface that manages the digital media store on the Apple iPad, iPhone, and iPod. The iTunes player is automatically interfaced to the Apple store where users can rent or buy movies to add to their iTunes library. The player can also add movies to the library that is already stored on a personal computer. A common task for iTunes users is adding movies to the player. How to Read More

Many people find themselves in the position of either registering for an email account for the first time or wanting to switch to an alternative email host. Either way, these people should be careful to not fall victim to several email hosts who try to con prospective email users into paying for their services. There are dozens, if not hundreds, of free email hosting services available on the Internet for anyone to join at any time. The majority of these email hosts also do not have any restrictions on how Read More

Spread spectrum clocking is a technique used in synchronous digital devices that limits the amount of electromagnetic interference or EMI that the device causes. Since synchronous digital devices often generate interference levels that are not compliant with regulations that the FCC and other agencies set, spread spectrum clocking is an essential component of most small electronics. How Spread Spectrum Clocking Works Spread spectrum clocking works by distributing the bandwidth of electronic devices across many different frequencies simultaneously rather than allowing the device to emit EMI on any single frequency. Spread Read More