Tech Like I'm Five blogBig tech ideas, explained simply.2026-10-02T00:00:00Zhttps://blog.techlikeimfive.com/Tech Like I'm FiveWelcome to the blog!2026-10-02T00:00:00Zhttps://blog.techlikeimfive.com/welcome/What this blog is for, and what's coming next.<p>Hi there! This is the blog for <strong>Tech Like I'm Five</strong>, the YouTube channel that explains tech the way you'd explain it to a five-year-old: one idea at a time, with big pictures and small words.</p>
<p>The videos are short on purpose. This blog is where the extras go:</p>
<ul>
<li><strong>Cheat sheets</strong> you can come back to after watching a video</li>
<li><strong>"Wait, but what about...?"</strong> answers to good questions from the comments</li>
<li><strong>Behind the scenes</strong> notes on how the videos get made</li>
</ul>
<blockquote>
<p>Fun fact: you're reading this on <strong>blog.techlikeimfive.com</strong>. That's a <em>subdomain</em>, so it gets its very own DNS record. Price of a subdomain: $0.00.</p>
</blockquote>
<p>The first episode is all about DNS, the internet's Contacts app. <a href="https://www.youtube.com/@techlikeimfive">Go watch it on YouTube</a>, then come back for the cheat sheet.</p>
DNS cheat sheet: everything from the video on one page2026-10-02T00:00:00Zhttps://blog.techlikeimfive.com/dns-cheat-sheet/The quick-reference version of "DNS Explained... Like I'm Five." Records, TTL, IPv4 vs IPv6, subdomains and aliases.<p>Just watched <strong>DNS Explained... Like I'm Five</strong>? Here's the whole thing on one page.</p>
<h2>The big idea</h2>
<p>DNS is like the <strong>Contacts app on your phone, but for computers</strong>. You don't memorize your mom's phone number; you just tap "Mom" and your phone looks up the number for you.</p>
<p>Computers are terrible with names. They talk to each other using numbers called <strong>IP addresses</strong>. When you type a name like <code>techlikeimfive.com</code> into your browser, your browser asks a DNS server, "What's the number for this name?" and then connects to that number.</p>
<h2>DNS records</h2>
<p>Each contact in DNS is called a <strong>record</strong>. When you set up a new website, you add records at the DNS servers that are <strong>in charge of your domain</strong>. Until you do, every other DNS server says: <em>"Never heard of it."</em></p>
<table>
<thead>
<tr>
<th>Record</th>
<th>What it does</th>
<th>Example</th>
</tr>
</thead>
<tbody>
<tr>
<td><code>A</code></td>
<td>Points a name at an <strong>IPv4</strong> address</td>
<td><code>203.0.113.10</code></td>
</tr>
<tr>
<td><code>AAAA</code> ("quad A")</td>
<td>Points a name at an <strong>IPv6</strong> address</td>
<td><code>2001:db8:85a3::8a2e:370:7334</code></td>
</tr>
<tr>
<td><code>CNAME</code></td>
<td>Makes a name an <strong>alias</strong> of another name</td>
<td><code>blog.techlikeimfive.com</code> could be set up to be an alias, if we wanted to host the blog with a hosted blog service.</td>
</tr>
</tbody>
</table>
<p><em>(These are special example addresses that are set aside for documentation, so they never belong to a real computer.)</em></p>
<h2>TTL: patience, please</h2>
<p>Once a DNS server looks up an answer, it remembers it for a set amount of time, called the <strong>TTL</strong> (time to live). That's why a brand-new or changed record can take a little while to show up everywhere: some servers are still remembering the old answer (even an old "never heard of it") until their TTL runs out.</p>
<h2>IPv4 vs IPv6</h2>
<ul>
<li><strong>IPv4</strong> addresses are <strong>32 bits</strong> long. That makes 4,294,967,296 addresses (about 4.3 billion), and we've basically run out. <em>Sold out!</em></li>
<li><strong>IPv6</strong> addresses are <strong>128 bits</strong> long. That makes 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses (about 340 <em>undecillion</em>). That's... <strong>a lot.</strong> We're not running out of those.</li>
</ul>
<p>IPv6 has so many more addresses simply because each address is longer.</p>
<h2>Subdomains</h2>
<ul>
<li><code>techlikeimfive.com/blog</code> is a <strong>path</strong>. It uses the main domain's record, so it goes to the same servers as the main site.</li>
<li><code>blog.techlikeimfive.com</code> is a <strong>subdomain</strong>. It gets its own DNS record, so it can point somewhere completely different.</li>
</ul>
<p>Subdomains cost $0.00. Even <code>www.</code> is one!</p>
<h2>Aliases (CNAME)</h2>
<p>Michael, a.k.a. Mike: same guy, two names. A <strong>CNAME</strong> record works the same way. If a blog service names your blog something long like <code>techlikeimfive.bloghost.example</code> (that's a mouthful), a CNAME lets <code>blog.techlikeimfive.com</code> be a short, friendly alias for it.</p>
<p>One rule: a CNAME can't go on the bare domain (<code>techlikeimfive.com</code> itself), which is why the alias goes on a subdomain like <code>blog.</code>.</p>
<hr />
<p>What tech topic should we explain next? Let us know in the YouTube comments!</p>