IT Glossary: Technical Terms – H

#1: Hub

What is a hub? A hub is a device that connects several computers or other network devices (e.g. printers) to each other – essentially a multiple socket for the internet instead of for electricity. However, hubs are more of a ‘retro tech’ and were very popular in the 90s and 2000s.
Since they are not “intelligent” (when a computer sends data via a hub, it distributes it to all connected devices, regardless of who is actually supposed to receive it), they are now only used in small (home) networks. They have been almost completely replaced by switches, which work in a more targeted and efficient manner.

#2: Hypervisor

What is a hypervisor? It is a specific type of software that enables multiple virtual computers to run on a single physical computer. For example, several VMs can run on a powerful server, each with its own operating system – as if they were separate computers. The hypervisor also ensures that certain ‘rules’ are followed and that all resources are distributed according to demand.
The advantage of VMs: Virtual servers save space, electricity and money – and Windows and Linux, for example, can run simultaneously on one computer.

There are also two different types of hypervisors:

• the ‘bare metal’ type, which runs directly on the hardware without an operating system in between (e.g. VMware ESXi or Microsoft Hyper-V), and
• the hosted type, which runs within a normal operating system (e.g. VirtualBox, VMware Workstation).

More information on VMs and virtualisation can also be found in our blog post: ‘Powerful rack servers as VMs offer many advantages’.

#3: Heat sink

What is a heat sink? A heat sink is a component that dissipates heat from electronic components to prevent them from overheating. Many people are familiar with metal processor coolers, which have numerous fins or ribs to dissipate heat as efficiently as possible into the ambient air. In addition to these, heat sinks are also used in graphics cards (GPUs), motherboard voltage converters and on chips on certain adapters.

To find out what else is inside a server, read our blog post ‘Server components at a glance’.

#4: HTML

What is HTML? HTML stands for HyperText Markup Language – a special language for websites. Specific abbreviations and combinations tell the browser what to display on a page and how it is structured (e.g. plain text, bold text, colours, images, links, headings, etc.).
HTML works closely with CSS (design) and JavaScript (interactivity). The ‘HTML language’ consists of so-called tags that frame content, such as
<h1>Welcome to the Serverando blog </h1>
Since every browser understands HTML, this type of structuring is the basis for every website – whether it's a blog, shop or streaming platform.

#5: Home computers

What is a home computer? Let's dive back into retro tech: a home computer was an affordable, easy-to-use computer that was available for private use from the late 1970s to the early 1990s. Not many households could afford a PC at the time, which made these computers, which could be used for word processing, simple office tasks and games, all the more hyped. Well-known models include the Commodore 64 (1982), the Amiga 500 (1987) and the Apple II (1977).

#6: Hash function

What is a hash function? The term describes a mathematical algorithm that generates a compact, fixed output value from an input of any length (e.g. text, password, file). This value is called a hash value.
It is a type of encryption: for example, if you enter ‘Hello Serverando’, a hash value such as ‘4s276ab86k’ could be produced – if you remove just one space or one letter, a completely different value is produced.
However, the length of the hash value always remains the same. This means that you can use the hash value as code, but you cannot ‘convert’ the information entered back from the hash value. This function is used, for example, in password storage (storing the hash value instead of the actual password), data integrity (checking whether a file – such as a download – has been modified), blockchains (each block ID is a hash value of the previous block) and digital signatures, e.g. for verifying messages.

#7: Homebrew

What does homebrew mean? This term takes us into the world of gaming. Homebrew refers to self-developed software or games that are not officially produced by the manufacturer.
This includes, for example, digital creations for consoles or handhelds – such as a platform game programmed by a fan that runs on a homebrew channel.
This is not entirely legal, as manufacturers naturally only want to allow their own games. Homebrew developers therefore have to circumvent restrictions in order to run their own programmes – and this is where the legal grey area begins.
As long as no pirated copies are involved, it is not necessarily illegal, but it is frowned upon.

#8: Host

What is a host? A host is generally understood to be a computer system that provides services or resources in a network.
However, the term ‘host’ describes different types: There is a dedicated host – i.e. a server that is used, for example, in a company and is only used by that company (e.g. for data backup or management).
A virtual host, on the other hand, is often not a physical device, but a cloud platform on which, for example, several websites (and users) share the same server. If a person provides a game server, e.g. for Minecraft, this is a host on which various other players can play games. Online host providers (e.g. Strato, IONOS) provide databases or services so that you can host your own website, for example.

Hosting or your own server? You can find more information on this topic in our article ‘Server sales consultant – tips and information for your company’.

#9: Harddisk

What is a hard disk? A hard disk (or HDD) is a magnetic storage medium for permanently storing data. This data is retained even when the computer is switched off.
The HDD consists of rotating magnetic disks on which a read/write head writes or reads data. It is a rather ‘older’ storage format – there are now more modern variants such as SSDs or NVMes. However, it is still a widely used option for storing data, as the media, which now provide 20 TB or more of storage space, offer very good value for money. While SSDs or NVMes have relatively high capacity/price levels, HDDs – although slower – are cheaper per GB.

You can find out how the HDD has developed and what its predecessors and successors are in our blog post ‘Evolution of data storage – from 40,000 BC to today’.

#10: HTTP

What is HTTP? HTTP stands for Hypertext Transfer Protocol and is essentially the ‘language’ that a web browser uses to communicate with a web server in order to load a page.
The ‘protocol for transferring hypertext’, as it would be called in German, is therefore a kind of ‘ordering system’ that regulates how a website is displayed. When you enter a website in the address bar of your browser (e.g. http://www.serverando.de), the browser sends an HTTP request to the server. The server responds with the requested content and then displays – in this case – our online shop. However, HTTP has now been replaced by the HTTPS standard, because while the former does not offer encryption and only uses port 80, HTTPS is considered much more secure thanks to its (TLS/SSL) encryption and uses port 443.