when you see a website that’s HTTPS rather than HTTP, it means the connection is secure. most popular browsers will display a green padlock in the URL bar to symbolise that (and colour it yellow or red if something’s wrong). to verify that a connection is secure (and not just… Read More »Lynne Teaches Tech: What does HTTPS mean?
Lynne Teaches Tech
CP/M, a very old operating system for very old computers, used drive letters to distinguish between each drive on a computer. the first drive would be drive A, then drive B, and so on. CP/M computers typically had two floppy disk drives (drive A and B). when a CP/M machine… Read More »Lynne Teaches Tech: Why does Windows install to drive C by default? Why not A?
Lynne Teaches Tech: Why does text on a webpage stay sharp when you zoom in, even though images get blurry?
images like PNG and JPEG files get blurry when zoomed in beyond 100% of their size. this is true of video files, too, and many other methods of representing graphics. this is because these files contain an exact description of what to show. they tell the computer what colour each… Read More »Lynne Teaches Tech: Why does text on a webpage stay sharp when you zoom in, even though images get blurry?
paraphrased Wikipedia quote:In 1991, the Linux kernel appeared. Combined with the operating system utilities developed by the GNU project, it allowed for the first operating system that was free software, commonly known as Linux. in other words, the linux kernel and GNU utilities work together to form the linux operating… Read More »Lynne Teaches Tech: Why do people say GNU/Linux or GNU+Linux?
most people count using a decimal system. the lowest digit is 0, followed by 1, 2, and so on, through to 9. when you’re counting up and you reach nine, you need to add another digit. there’s no way to express ten with only one digit, so you use two… Read More »Lynne Teaches Tech: What’s an integer overflow?
Lynne Teaches Tech: Why does compressing a JPEG make it look worse, even though putting in a ZIP file makes it look the same?
there are many different methods of file compression. one of the simplest methods is run length encoding (RLE). the idea is simple: say you have a file like this:aaabbbbaaaaayou could store it as:a3b4a5to represent that there are 3 a’s, 4 b’s, etc. you would then simply need a program to… Read More »Lynne Teaches Tech: Why does compressing a JPEG make it look worse, even though putting in a ZIP file makes it look the same?
keybase is a website that allows you to prove that a given account or website is owned by you. to explain how this works, we’ll need to briefly cover public key cryptography. there are many ways to encrypt a file. one such way involves using a password to encrypt the… Read More »Lynne Teaches Tech: What’s Keybase?
when you access a website in your browser, its URL (Universal Resource Location) will almost always start with either https:// or http://. this is known as the schema, and tells the browser what type of connection it’s going to be using, and how it needs to talk to the server.… Read More »Lynne Teaches Tech: What do all the parts of a URL or hyperlink mean?
a web browser is a program that displays a HTML document, in the same way that a text editor is a program that displays a txt file, or a video player displays MP4s, AVIs, etc. HTML has been around for a while, first appearing around 1990. HTML alone is enough… Read More »Lynne Teaches Tech: Why are there so few web browsers?
“defrag” is short for “defragment”. when a file is saved to a hard drive, it is physically written to the device by a needle. when you need to read the file, the needle moves along the portion of the disk that contains the data to read it. let’s say you… Read More »Lynne Teaches Tech: What’s “defragging”?