After you have [[learned|00001007903000]] the basic concepts and markup of Zettelmarkup (paragraphs, emphasized text, and lists), this zettel introduces you to the concepts of links, thematic breaks, and headings.

=== Links
A Zettelstore is much more useful, if you connect related zettel.
If you read a zettel later, this allows you to know about the context of a zettel.
[[Zettelmarkup|00001007000000]] allows you to specify such a connection.
A connection can be specified within a paragraph via [[Links|00001007040310]].

* A link always starts with two left square bracket characters and ends with two right square bracket characters: ''[[...]]''.
* Within these character sequences you specify the [[zettel identifier|00001006050000]] of the zettel you want to reference: ''[[00001007903000]]'' will connect to zettel containing the first steps into Zettelmarkup.
* In addition, you should give the link a more readable description.
  This is done by prepending the description before the reference and use the vertical bar character to separate both: ''[[First Steps|00001007903000]]''.

You are not restricted to reference your zettel.
Alternatively, you might specify a URL of an external website: ''[[Zettelstore|https://zettelstore.de/]]''.
Of course, if you just want to specify the URL, you are allowed to omit the description: ''[[https://zettelstore.de/]]''

|= Zettelmarkup | Rendered output | Remark
| ''[[00001007903000]]'' | [[00001007903000]] | If no description is given, the zettel identifier acts as a description
| ''[[First Steps|00001007903000]]'' | [[First Steps|00001007903000]] | The description should be chosen so that you are not confused later
| ''[[https://zettelstore.de/]]'' | [[https://zettelstore.de/]] | A link to an external URL is rendered differently
| ''[[Zettelstore|https://zettelstore.de/]]'' | [[Zettelstore|https://zettelstore.de/]] | You can use any URL your browser is able to support

Again, you probably see a principle.

=== Thematic Breaks
[[And now for something completely different|https://en.wikipedia.org/wiki/And_Now_for_Something_Completely_Different]].

Sometimes, you want to insert a thematic break into your text, because two paragraphs do not separate enough.
In Zettelmarkup this is done by entering three or more hyphen-minus characters at the beginning of a new line.
You must not include blank lines around this line, but it can be more readable, if you want to look at the Zettelmarkup text.

```zmk
First paragraph.
---
Second paragraph.
```

```zmk
First paragraph.

---

Second paragraph.
```

Both are rendered as:
:::example
First paragraph.
---
Second paragraph.
:::

Try it!

This might be the time to relax a rule about paragraphs.
You must not specify a blank line to end a paragraph.
Any Zettelmarkup that must start at the beginning of a new line will end a previous paragraph.
Similar, a blank line must not precede a paragraph.

This applies also to lists, as given in the first steps, as well as other [[similar markup|00001007030000]] you will probably use later.

=== Headings
Headings explicitly structure a zettel, similar to thematic breaks, but gives the resulting part a name.

To specify a heading in Zettelmarkup, you must enter at least three equal signs, followed by a space, followed by the text of the heading.
Everything must be one the same line.

The number of equal signs determines the importance of the heading: less equal signs means more important.
Therefore, three equal signs treat a heading as most important.
It is a level-1 heading.
Zettelmarkup supports up to five levels.
To specify such a heading, you must enter seven equal signs, plus the space and the text.
If you enter more than seven equal signs, the resulting heading is still of level 5.

See the [[description of headings|00001007030300]] for more details and examples.