The **zarf format** is similar to other **archive formats**, such as the **ar format**, the **cpio format**, the **shar format**, the **tar format**, and the **WARC format** — but is designed to be easier to understand and implement than all of the other **archive formats** and **container formats**.
There are many many use-cases where multiple files are combined into a single file.
For example:
* backups,
* eBooks,
* file-systems,
* image galleries,
* journals,
* music albums,
* photo albums,
* software packages,
* website archives,
* _etc_.
Many of these use-cases either use the **cpio format**, the **rar format**, **tar forat**, or the **zip format**.
While all of these formats work acceptably as an **archive format** and a **container format** — none of them are **easy** for a programmer of 3 to 10 years of experience to implement a encoder and a decoder for it.
Also none of these supports a ‘**view-source**’ learning style (as none of them is text based, for some definition of "text").
Although **zarf** does _not_ require an extension (since it has magic-bytes), if a file-extension is used for a **zarf** file, it should use the `.zarf` extension (on systems where file-extensions are necessary).
Although **zarf** does _not_ require a MIME-type (since it has magic-bytes), f a MIME-type is used for a **zarf** file, it should use the `multipart/zarf` extension (on systems where file-extensions are necessary).
A **zarf** file is a single file that contain multiple other files.
Or said more formally, the **zarf format** is an **archive format** and **container format** that can combine multiple files into a single aggregate file.
One of the main points of the **zarf format** is that it was designed to be easy to understand and implement for programmers.
The **zarf format** is meant to be both programmer-legible and programmer-friendly.
The common way to store and think about **multiple files** is as part of a directory system.
For example:
* readme.xhtml
* LICENSE
* images/logo.png
* images/banner.png
* images/figures/figure1.jpeg
* images/figures/figure2.jpeg
* images/figures/figure3.png
This type of thing (and the files' contents) is what is inside of a **zarf** file.
One way of thinking about this is that, it is a **hierarchical key-value format** similar to (**but not the same as**) JSON, INI, and other similar formats.
For example, in JSON the preceding file system would probably look like:
```json
{
"readme.xhtml": "...",
"LICENSE": "...",
"images": {
"logo.png": "...",
"banner.png": "...",
"figures": {
"figure1.jpeg": "...",
"figure2.jpeg": "...",
"figure3.png": "..."
}
}
}
```
(Note that we are using `"..."` in the examples because we aren't listing the contents of the files.)
Also for example, in INI the preceding file system would look like:
```ini
readme.xhtml = ...
LICENSE = ...
[images]
logo.png = ...
banner.png = ...
[images.figures]
figure1.jpeg = ...
figure2.jpeg = ...
figure3.png = ...
```
(Again note that we are using `"..."` in the examples because we aren't listing the contents of the files.)
Now let's look at a **zarf** file that actually includes each file's contents (instead of `"..."`) so we can see a real example.
We are going to use a different directory structure or this example though.
We will use this one:
* README.md
* article.txt
* images/logo.svg
And here is the example **zarf** file that includes each of the file's contents (instead of `"..."`):
```
ZARF/1
README.md
12
Hello world!
article.txt
1572
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Interdum velit laoreet id donec ultrices tincidunt arcu non sodales. Cras semper auctor neque vitae tempus quam pellentesque nec nam. Cursus turpis massa tincidunt dui ut. Diam vel quam elementum pulvinar etiam non quam. Gravida neque convallis a cras semper. Ornare massa eget egestas purus. Tempor id eu nisl nunc mi ipsum faucibus vitae aliquet. Fames ac turpis egestas maecenas pharetra. Arcu bibendum at varius vel pharetra vel turpis nunc. Integer quis auctor elit sed vulputate mi. Eget velit aliquet sagittis id consectetur purus ut faucibus. Sapien pellentesque habitant morbi tristique senectus.
Lorem mollis aliquam ut porttitor leo a diam sollicitudin tempor. Quis commodo odio aenean sed adipiscing. Commodo quis imperdiet massa tincidunt nunc. Quam quisque id diam vel quam elementum pulvinar etiam non. Elit ut aliquam purus sit amet luctus venenatis lectus. Sit amet mauris commodo quis. Placerat vestibulum lectus mauris ultrices eros in. Tristique sollicitudin nibh sit amet commodo nulla facilisi nullam vehicula. Augue interdum velit euismod in. Tellus pellentesque eu tincidunt tortor. Commodo viverra maecenas accumsan lacus vel facilisis. Venenatis a condimentum vitae sapien pellentesque habitant morbi. Et ligula ullamcorper malesuada proin libero nunc consequat interdum varius. Tellus integer feugiat scelerisque varius. Bibendum enim facilisis gravida neque convallis. Nisl nisi scelerisque eu ultrices vitae auctor eu.
