Imagine that when you open the front door of your home, you might find yourself on any street in the world. That's how a computer works. Poor security can give away the keys to your life.
A password's strength can be measured in bits of entropy. A short password with only letters and numbers doesn't have many bits: it's weak. A longer password with more variation has more bits: it's stronger.
It's very hard for us to remember strong passwords. If it's easy to remember, it's easy to crack. Password cracking is where people use computers to figure out your password. If you can remember your password (for example, it's your pet's name and the year someone you love was born), then it's quite likely someone will write a computer program that can figure it out, based on your social media, or your friends' social media.
If you want to prevent people breaking in to your accounts, you need to use strong, unique passwords for every site, especially your email accounts.
Password managers generate strong, unique passwords for every site, and remember them for you. You should use one. There are several:
You will still need to remember the password to your password manager, but now you can forget the rest.
A strong password has several bits of entropy: the more the merrier. Think of four or more words that have nothing to do with each other, except in your brain. Silently repeat them to yourself, many times. Don't use existing song lyrics, or lines from a poem or a book or a blog. Those can be guessed.
For example: correct horse battery staple
Choose your own!
The only way to know who controls a web site is by the domain name.
A domain name is part of a URL, which you can find in the address bar of your browser, or by copying a link and pasting it somewhere.
If a web site is not encrypted, then people can see everything you see, and everything you send to the site. Therefore you should always pay attention to whether the sites you visit are encrypted. If the URL begins with http instead of https, then it's not encrypted. Even if it does begin with https, it's only encrypted if the site's certificate is valid and up to date. You will often see a padlock icon to indicate whether a web site is encrypted. You can click on the padlock icon to see information about the web site's domain name and certificate. If a certificate is no longer valid, some browsers will show an icon to indicate that.
Even if the web site's domain belongs to the organization you think it does, and they have encrypted the web site, you should only interact with web sites that belong to organization you trust to engage in business with you honestly. If you do not trust someone, then a web site certificate should not override that.
You definitely should not enter any passwords, credit card numbers, or personal information on sites that are not encrypted. If you do, you are broadcasting that information for the world to see.
Personal information includes names, phone numbers, email addresses, physical addresses, passwords, usernames, account numbers, PIN numbers, government ID numbers, student ID numbers, and many other things you might not think about (like GPS coordinates that are included in most photos).
Be very careful with personal information! Once you post it publicly you cannot prevent anyone from copying it. Even if you think you did not share it publicly, you may have done so accidentally. If you share a photo that shows some mail with your address on it, or you enter your address into an online store that's not encrypted, you have broadcast your address to the world.
Avoid sharing personal information, except when you must. Even then, you should feel free to pause, and think about whether you want to interact with someone. Do not ever feel pressured to provide information to someone over the Internet or on the phone with personal information immediately. You're allowed to take time to think about it, and call them back later if you decide to.
You should separate your work and personal data as much as possible, to avoid legal complications, and provide an example of professionalism. If you can, use separate devices for work and personal use.
If your devices belong to your employer, you should still avoid using your work email for personal communication. Instead, use a personal email.
As a side note, keep your emails brief, use the subject line, and keep different subjects in separate threads for easy reference later. This shows people that you respect their valuable time.
You can choose what you read, or watch, or listen to. It's easy to let others choose for you, but then you allow them to control the direction of your life. The difference between you now, and you in the past, is the people you've met and the books you've read.
You can create your own news feed using a feed reader like Feedly. It's free. Create an account and add some sites you enjoy.
These sites allow you to discover the wealth of knowledge in the world:
- Internet Archive
- Librivox: free, public domain audiobooks
- Open Culture
- Project Gutenberg
- Wikipedia: free-content encyclopedia
- YouTube
Pocket lets you save articles to read later.
The worst lie told in school is that Wikipedia is inaccurate. It is just as accurate as the Encyclopedia Britannica, and covers far more. Wikipedia is a summary of the most influential books and publications in history, with references. It is not just made up: people continuously check it for errors, and ruthlessly correct them. You can try to vandalize it, but anyone can see what you did by looking at the page history, and your edits will be reverted if they're not factual. Use it like a map: it can show you the way to the best sources of information. All maps have some inaccuracies, but they are still useful. The map is not the territory.
Don't let yourself sit in a rut. Explore, learn, create, and share!
If you want to know more about how computers work, check out Free Code Camp.
There are many different kinds of computers that affect your every day life, some of which you will never see.
A server is just a computer that communicates with other computers, and may not have a screen or a keyboard or pointing device attached at all. Whenever you use a computer, it is probably communicating with many servers.
A datacenter is just a bunch of servers in a room or a building, designed to hold a bunch of servers.
The cloud is just a bunch of datacenters.
Desktop and laptop computers (sometimes called workstations) are designed for a person to use directly. They almost always include a keyboard and a pointing device. Sometimes they have touchscreens, but not always. They use a style of graphical user interface (GUI) called WIMP (Windows, Icons, Menus, Pointer). They also have command line interfaces (CLIs), which are very useful for programming and interacting with servers.
Smartphones usually have touchscreens, and not many buttons. They use graphical user interfaces (GUIs), and rarely include command line interfaces (CLIs). They are easier to use than desktop and laptop computers, but in some ways they are less capable.
Tablets are basically giant smartphones. Although you can write computer programs on a smartphone or a tablet, most professional programmers prefer a desktop or a laptop. Those who use tablets for programming usually connect to a remote server and run their programs there, which means you need to have a stable Internet connection to be productive. On a desktop or a laptop, you can easily write programs with intermittent Internet access.
Voice assistants are included in most smartphones, and some desktops and laptops. There are also standalone devices designed for voice input, some of which don't have screens. Alexa, the Google Assistant, and Siri are the most popular.
Alexa and the Google Assistant record what they hear, and use those recordings to target advertising to you. Siri does not share information with advertisers.
Embedded computers are all over the place: in your car, fridge, stove, toaster, maybe even your lightbulbs. Security is just as important for these devices as it is for every other computer. Pay attention to which manufacturers you trust.