<!DOCTYPE>
Defines the document type.
<!DOCTYPE>
<html>
Defines an HTML document.
<html> Page content </html>
Page content
<head>
Contains metadata and information for the document.
<head> <meta charset="utf-8"> </head>
<title>
Defines a title for the document.
<title> Handbook </title>
<body>
Defines the document's body.
<body> Main content </body>
Main content
<h1> to <h6>
Defines HTML headings.
<h1> Title of the first level </h1>
Title of the first level
<p>
Defines a paragraph.
<p> Place text here </p>
Place text here
<br>
Inserts a single line break.
<p> First line <br> Second line </p>
First line
Second line
<hr>
Defines a thematic change in the content.
<hr>
color
Sets the color of a text.
color: RGB, hex, keyword;
Red color text
line-height
Sets the distance between lines.
line-height: normal, number, length, %;
This text has line height of 50 pixels
letter-spacing
Increase or decrease the space between characters.
letter-spacing: normal, length;
This text has letter spacing of 5 pixels
text-align
Aligns the text in an element.
text-align: left, right, center, justify;
This text is aligned by right side
text-decoration
Adds decoration to text.
text-decoration: none, underline, overline, line-through;
This text is underlined
text-transform
Controls the letters in an element.
text-transform: none, capitalize, uppercase, lowercase;
This text is uppercased
border
Sets all the border properties in one declaration.
border: border-width, border-style, border-color;
This text has 1 pixel dashed red border line
font-family
Specifies the font family for text.
font-family: family-name, generic-family, inherit;
This text is written in the monospace font
font-size
Specifies the font size of text.
font-size: xx-small, x-small, small, medium, large, x-large, xx-large, smaller, larger, length, %, inherit;
This text has size of 22 pixels
font-weight
Specifies the weight of a font.
font-weight: normal, bold, bolder, lighter,
100, 200, 300, 400, 500, 600, 700, 800, 900, inherit;
This text has a font width of 900
HTTP/HTTPS
HTTP defines a set of request methods to indicate the desired action to be performed for a given resource. Although they can also be nouns, these request methods are sometimes referred to as HTTP verbs. Each of them implements a different semantic, but some common features are shared by a group of them: e.g. a request method can be safe, idempotent, or cacheable.
HTTPS is an encrypted version of the HTTP protocol. It uses SSL or TLS to encrypt all communication between a client and a server. This secure connection allows clients to safely exchange sensitive data with a server, such as when performing banking activities or online shopping.
Request Methods
GET – requests a representation of the specified resource. Requests using GET should only retrieve data.HEAD – asks for a response identical to that of a GET request, but without the response body.POST – used to submit an entity to the specified resource, often causing a change in state or side effects on the server.PUT – replaces all current representations of the target resource with the request payload.DELETE – deletes the specified resource.CONNECT – establishes a tunnel to the server identified by the target resource.OPTIONS – used to describe the communication options for the target resource.TRACE – performs a message loop-back test along the path to the target resource.PATCH – used to apply partial modifications to a resource.
Response Status Codes Classes
100-199 – Informational responses.200-299 – Successful responses.300-399 – Redirects.400-499 – Client errors.500-599 – Server errors.
DNS
DNS is a hierarchical and decentralized naming system for Internet connected resources. DNS maintains a list of domain names along with the resources, such as IP addresses, that are associated with them.
Commonly Used Record Types
A (Host address) – The A-record is the most basic and the most commonly used DNS record type. It is used to translate human friendly domain names such as "www.example.com" into IP-addresses such as 23.211.43.53 (machine friendly numbers).AAAA (IPv6 host address) – An AAAA-record is used to specify the IPv6 address for a host (equivalent of the A-record type for IPv4). IPv6 is the future replacement for the current IP address system (also known as IPv4).ALIAS (Auto resolved alias) – ALIAS-records are virtual alias records resolved by Simple DNS Plus at at the time of each request - providing "flattened" (no CNAME-record chain) synthesized records with data from a hidden source name. This can be used for different purposes - including solving the classic problem with CNAME-records at the domain apex (for the zone name / for "the naked domain").CNAME (Canonical name for an alias) – CNAME-records are domain name aliases. Computers on the Internet often performs multiple roles such as web-server, ftp-server, chat-server etc. To mask this, CNAME-records can be used to give a single computer multiple names (aliases).MX (Mail eXchange) – MX-records are used to specify the e-mail server(s) responsible for a domain name. Each MX-record points to the name of an e-mail server and holds a preference number for that server. If a domain name is handled by multiple e-mail servers (for backup/redundancy), a separate MX-record is used for each e-mail server, and the preference numbers then determine in which order (lower numbers first) these servers should be used by other e-mail servers.
IP Address
An IP address is a number assigned to every device connected to a network that uses the Internet protocol. "IP address" typically still refers to 32-bit IPv4 addresses until IPv6 is deployed more broadly.
Find the IP address of a website on Mac
- Click on the spotlight icon.
- Type Network Utility.
- Double click on the Network Utility.
- Tap Traceroute.
- Enter your website address.
- Click on Trace.