Normally when you email something, you can't know if someone opened it. Because you basically tell the email company, "tell them I said X".

So to get around this, you put in a specific address to a website that you control.

When someone opens the email, it'll be told "automatically load the picture from this website", where the picture is a single dot. Their email program "fetches" the dot.

When you go to check to see if they read the email, you can see when they opened the email because that's when the email program asks your website to show the picture (and logs it).

What this guy is saying is that instead of asking your website to keep loading that dot each time, it'll do it the first time and then just save the picture.

Stop trying to make fetch happen!

I got you

Fetch()

it's a function in JavaScript (and some other languages) for interacting with a database, especially with APIs (Application Programming Interface). These interactions include acquiring/pulling/fetching data, uploading data, editing data, and deleting data.

Since API is a loaded term and I'm not sure how familiar with computer science you are let's think of it like meal prepping. When you meal prep you create a large portion of a meal that you can pull from into any meal you feel like making that day. An API is similar in nature. An API is created by developers with code or processes they expect to need down the road.

For example if I want to pull data from a database I would create an API that allowed me to just pull from the database. Now that I've created an API to pull from the database other developers can use my API in their programs to pull from the database without having to reinvent what I just made. It saves time just like meal prepping.

Hope this answered the things!

Edit: changed some commas to slashes /