Listserv was one of the earliest and most influential electronic mailing list applications. Released in 1986, the application is still going strong and in wide use around the world. Listserv introduced a wide variety of email list management features we take for granted today, such as automated subscribing and unsubscribing without the intervention of a human list curator, message templates, and spam filtering.
An electronic mailing list is a method of using email that allows for easy and widespread distribution of information to members of the list. There are two common forms of electronic mailing lists: distribution lists and announcement lists.
The junk folder (also known as the spam folder) is a folder found in the inboxes of most modern email services where emails that have not been outright rejected by the email provider’s global spam filters, but which appear suspicious (because they, for example, contain marketing terms and the sender is not in the recipients address book or address whitelist), are dumped for further review. This is why companies will frequently request you check your junk folder for emails that you have reported as unreceived, as legitimate commercial communications can often end up accidentally caught in the spam-hunting algorithms.
A bounce message is a form of auto-response sent to the sender of an email when the email cannot be delivered to the intended recipient. Although informally referred to as a bounce message, the message is technically known as a Non-Delivery Report (NDR). The message typically contains the date and time the original email was bounced, the identity of the mail server it bounced at, the reason for the bounce (e.g. mailbox full, user unknown, etc.), the headers of the bounced message, and a full or partial reprint of the original bounced message.
Email autoresponders are computer programs that automatically answer email. Autoresponders fall into two categories: infrastructure and user-definable. Infrastructure-based autoresponders are the responders that send you helpful automated messages like those you received when an email sent to a given domain cannot be delivered. User-definable responders most typically take the form of vacation away messages that indicate to the sender that the recipient is out of the office for an extended period of time. Other common user-defined responders include automated messages received after joining mailing lists or confirmation of a purchase made.
A spider trap is a web page or set of pages that traps any web crawler/search bot that comes across it. While some spider traps are unintentionally created (e.g. there is an element on the page such as a dynamic calendar with, essentially, infinite forward links for the crawler to follow), many spider traps are created with the intent of trapping spam crawlers looking for email addresses and other personal information. The heart of the trap, whether intentionally or unintentionally created, is series of links or a dynamic link system that a crawler gets stuck following (like a maze with no exit).
Email harvesting is the process of amassing lists of email addresses, almost always to spam them, using disreputable practices such as purchasing email lists in bulk from resellers, using giveaway/contest websites to harvest emails, or using harvesting bots to crawl web pages, forum and usenet posts, and other publicly accessible locations, looking for email addresses to add to the list.
An email attachment is a file sent along with the email message. Early email systems required manual attachment encoding in wherein the user would have to use a program to convert the file into a block of text which could be pasted into the body of the email. Such attachments were terribly inconvenient and required that the recipient know how to turn the block of encoded text back into whatever it was (picture, spreadsheet, etc.)
In email composition, the “BCC:” section, short for Blind Carbon Copy, is a method of sending an email to additional addressees without alerting the primary addressees (and the potential secondary addresses in the “CC:” section) that the email has been shared beyond those listed on the email. The practice is a holdover from the days of paper letters and memos where a document within an organization would be intended for a specific recipient but could also have additional recipients (including those whose identity, for whatever purpose, needed to remain hidden from the other recipients).
In email composition, the “CC:” section, short for Carbon Copy, is a method of sending an email to additional addressees without inserting them into the primary “To:” section. While this might seem counter intuitive as it’s just as easy to put an email address in the “To:” section as the “CC:”, the practice is a holdover from the days of paper letters and memos where a document within an organization would be intended for a specific recipient but additional carbon copies could be sent to people who needed to stay abreast of the material. That same functionality remains in email: the primary recipient(s) go in the “To:” section and anyone else who needs to be aware of the communication but is not the primary recipient goes in the “CC:” section.
Email obfuscation is an attempt to make an email address difficult for spam bots to harvest and begin spamming. There are two forms of obfuscation: manual obfuscation and HTML-code obfuscation. In manual obfuscation, the user manually breaks up their email address using text that a human can easily read and decode but that wouldn’t form a valid address a spam bot could harvest. Thus, an email address like firstname.lastname@example.org might be written like someguy AT somehost DOT org; a human could read that but it wouldn’t register as an email address if a bot was scanning for a typical *@*.* email address format.
Biometrics refers to the technology (both hardware and software) used to identify individuals based on their physical characteristics. Fingerprint scanners, facial recognition, and voice analysis are all methods of turning the user’s physical characteristics into security checks.
In computer security slang, a “black hat” is a malicious computer hacker. Unlike their counterpart, the “white hat” hacker, black hats are those who would exploit security flaws for personal gain (or for the benefit of the corporation, organization, or nation state they work for).
In computer security slang, a “White Hat” is an ethical hacker. The term white hat is applied to individuals that seek out security flaws and then notify organizations so the security flaws can be remedied as well as hired security specialists who look over an organization’s infrastructure to find the security flaws before malicious users do.
In computer security, honeypots, like their real-world counterparts employed by law enforcement agencies, are traps set to detect or counteract authorized access to computer networks. Honeypots can take the form of individual computers, data sets, or network sites that appear to be valuable or worth investigating to the intruding party but which are actually designed to entrap and/or monitor the attacker.
Digital preservation is a form of data backup focused on ensuring continued future access to the digital information preserved by the backup process. Whereas a typical backup system is designed to simply duplicate the data so that it may be restored in the event the original data set or host computer is damaged, groups concerned with digital preservation are not just concerned with creating redundant copies of data but ensuring that future generations will be able to access that data.
A differential backup system backs up the changes made to a system between the initial backup and the current backup. Unlike an incremental backup system, wherein only the newest changes from the previous increment are recorded, the differential system backs up everything that has changed from the initial backup on each subsequent backup. One way to visualize this is to think of incremental backup data sets, where A is the initial backup, as A + B + C + D, whereas differential backups are A + B + BC + BCD.
Incremental backups make it feasible to store a higher number of backups in a limited amount of space by building on an initial complete backup. The data set is first completely backed up to the backup medium and then, at the scheduled backup times, the incremental changes to the data set are recorded. If using this backup model, the backup size will be the size of the entire data set plus whatever data has changed during the increment of time between the initial backup and the subsequent backups.
A full backup, or system image, is a backup of a computer system that includes not only user data stored on the machine (such as documents and photographs), but the entire operating system and installed applications. A full backup allows for a complete restoration of the system in the event of catastrophic failure.
Offline backup is a backup that is not accessible to the computer that initiated the backup process after the process is completed. If, for example, you backed up your data to an external hard drive but then removed the external hard drive and stored it, then the backup would be considered offline, as a catastrophe that could destroy the original data set (such as a power surge or malicious software) would not be able to touch the offline backup.
An online backup is a backup that is still accessible to the computer which initiated the backup process. For example, if you back up all your data from your personal computer to an external hard drive that remains attached to your personal computer at all times, it is, in the sense that it exists on two physical mediums, backed up.
A backup is a duplicate copy of a data set or entire hard drive that is stored on a separate storage medium from the source file (or disk). If the original data (say, family photos) is stored on the primary drive of a computer and those photos are copied onto a secondary drive, the data set on the secondary drive is the backup.
Inkjet printing is a process by which text and graphics are applied to a medium, typically paper, via a controlled and cold application of ink through micro-nozzles. Inkjet technology is used in a wide range of applications, including basic consumer home printing of small documents and the production of large banners; while the scale of the printer changes, the fundamental operation remains the same.
Electrostatic digital printing is the process by which laser printers apply images to paper. Inside the laser printer, a laser beam passes over an electrostatically charged drum; this laser beam changes the static charge on the drum to represent a portion of the image (be it text or graphics) sent to the printer. The drum then collects toner from the toner cartridge and the toner clings to the charged portion of the paper. The final step fuses the toner to the paper (if you’ve ever cleared a jam out of a laser printer and the toner dust wiped right off the page, the paper jammed before the fusing process).
A dye-sublimation printer is a printer that uses heat to transfer ink onto the print medium as opposed to inkjet printing which sprays micro droplets of ink onto the surface of the medium. The name is derived from the process itself, during the heating and application process the dye sublimates from a solid material to a gas without transitioning through a solid state.