If you're a tech person, this is probably all kid's stuff. Maybe you're very young and recently started programming, or maybe you're self-employed or a non-tech cofounder of a startup or small business who just wants to dip your toe into the tech side (a very smart thing). Either way the stuff isn't too hard to learn, and there's a lot of it, so mastering what you need to get an MVP (minimum viable product) going as quickly as possible is very important.
You've come to the right place. Let's dive right in.
HTML is verbose. Plaintext is unwieldy. WYSIWYG is inconsistent. Markdown to the rescue!
Oh wait, my blog runs on a custom script I wrote myself. Great, that means I can implement any feature I want with it. Crap, that means I have to implement any feature I want with it.
When you go to a website and the little padlock icon appears next to the URL, that shows two things: That you are interacting with the website over an encrypted connection, and that the website really is who it says it is. This dual-purpose nature of the HTTPS protocol (SSL or TLS) is why it has become a standard: it protects you in both ways. But it presents a huge gap in the way the internet can be used, and it's the browsers' fault (Chrome, Firefox, IE, Safari, etc). Practically all browsers treat this issue the same way, and it's the wrong way.
Sometimes, always, it's desirable to allow encryption without any identity guarantee. Of course, if a website wants to provide both, it can, and it should even be afforded special notice for being extra-secure. You want your bank and certain other websites to be as secure as possible, after all. However, little-guy web servers shouldn't be punished for wanting to protect the user by using encryption even if they can't or won't guarantee their identity (for various reasons), which is exactly what happens in all major browsers:
You would think that the financial service industry, of all industries, would not be the last one to keep up with technology, but it is. They certainly are adept at making new financial instruments, like credit-default swaps (CDS) and collateralized debt obligations (CDO), even if it causes the laxest lending standards in American history - and the highest foreclosure rate as a result.
Yet every time I deal with a bank, I am flabbergasted as to its total lack of technological aptitude. I'm reminded of my grandmother trying to use a web browser. It's like the ones that work for Wall Street and the ones that work for Main Street are of completely different generations.