Articles
The seven layers of the OSI model and their tasksNetwork · 8 minThe OSI model and TCP/IP — how a network hangs togetherIP addressing and subnetting explainedNetwork · 9 minIP addresses and subnetting are the foundation of all network design. Learn the difference between IPv4 and IPv6, what a subnet mask means, and why networks are divided into smaller parts.Professional IT support — from contact to solutionSupport · 7 minGood IT support is as much about structure and communication as it is about technology. Get an overview of the support process, escalation levels and how a case is properly documented.The operating system — the brain between hardware and userOperating systems · 8 minAn operating system controls all hardware and gives programmes and users a common basis to work on. Understand the core processes file system and permissions and you have a solid foundation for both operation and troubleshooting.Servers and virtualisation — one machine many servicesServers · 9 minA server provides services to other machines and virtualization lets you run many independent servers on the same physical hardware. Understand the role the common server types and the difference between virtual machines and containers.IT security in practice – protect data, users and systemsIT security · 8 minIT security is about protecting confidentiality, integrity and availability. Get an overview of the guiding principles, the common threats and the daily habits that make the biggest difference.GDPR in IT operations — what data protection means in your day-to-dayLegislation · 9 minAs an IT employee you handle personal data daily and the data protection regulation (GDPR) sets the framework. Understand the foundational principles what a processing basis is your obligations around security and what happens when a breach occurs.Service management according to ITIL — bring structure to operationsService management · 8 minITIL is the widespread framework for IT service management. Understand the difference between an incident, a problem, a change and a service request, what a service desk is, and how to measure service with agreed targets – so operations become predictable instead of firefighting.Backup That Works — Strategy, 3-2-1 and RecoveryOperation · 8 minA backup is only worth something if you can restore from it when it matters. Understand the 3-2-1 rule, the concepts of RPO and RTO, the difference between full and incremental backups, and why separation from the production system and testing of restoration is the most important of all.From telegraph to internet — the history of data communicationHistory · 11 minThe data communication trade is young, but it rests on over one and a half centuries of work sending information over distance. Follow the journey from the telegraph and the first transatlantic cable through ARPANET and packet switching to TCP/IP, the World Wide Web and the network you sit on today.Wireless networks — Wi-Fi standards and securityNetwork · 8 minWi-Fi officially stands for IEEE 802.11, and the standard has evolved through several generations with each their letter and eventually a simpler name. The article covers the generations, frequency bands and the security evolution from the insecure WEP to today's mandatory WPA3 — as well as the practical approaches that determine whether a wireless network actually works well in everyday life.Structured cabling — standards, categories and fibre opticsMaterials · 8 minBehind Every Stable Network Lies Well-Considered Cabling. The International Standard ISO/IEC 11801 (in Europe Supplemented by EN 50173) Describes How a Building Network is Structured and Which Cable Categories Exist. The Article Covers the Categories, the Difference Between Copper and Fibre, and Why Documentation is Just as Important as the Cable Itself.VLAN and switching — how a network is divided logicallyNetwork · 8 minA switch binds devices together at layer 2, but the more devices that share the same physical network, the more broadcast traffic and the worse security separation. VLAN (Virtual LAN) solves this by dividing one physical network into several logical ones. The article explains VLAN tagging according to the 802.1Q standard, the difference between access and trunk ports, and how traffic can still flow between VLANs when necessary.Firewall, IDS and IPS — the network's border guardIT security · 7 minA firewall is the most basic security component in a network but it exists in several versions with very different insight into traffic. IDS and IPS are related systems that monitor for suspicious activity — one alerts the other intervenes. The article explains the differences and the concept of DMZ a middle zone that protects internal systems.Encryption in practice — symmetric, asymmetric and certificatesIT security · 8 minEncryption protects data so only the right person can read it — but there are several basic approaches that each solve their own problem. The article covers symmetric and asymmetric encryption, why hashing is something completely different, and how all three techniques work together every time a browser shows a padlock at an HTTPS address.Cloud computing — IaaS, PaaS, SaaS and cloud modelsServers · 8 minCloud computing is not just 'other people's computers' — it is a well-defined model with three service levels and four deployment models which the US standards organization NIST has described in publication SP 800-145. The article covers IaaS, PaaS and SaaS, the difference between private, public and hybrid cloud and why the responsibility for security is always shared between provider and customer.Databases and SQL — how structured data is saved and retrievedProgramming · 8 minAlmost all software you encounter as a data technician or support staff stores its data in a relational database. The article introduces basic concepts – tables, rows, columns and keys – and shows how SQL is used to retrieve, insert and update data as well as why SQL injection is one of the most common security risks.Git and version control — how developers collaborate on codeProgramming · 7 minAs soon as more than one person writes code on the same project the need for version control arises. Git is today the most widespread tool for the purpose. The article explains what version control solves the basic concepts commit branch and merge and how branches and pull requests make it possible to work in parallel without destroying each other's work.Work environment at screen work — AT guidance in practiceWork environment · 7 minAs a data technician or IT support you sit a large part of the day at a screen — and the Working Environment Authority's AT guidance on screen work (D.2.3) applies just as much to you as when you advise others on their workplace. The article covers requirements for breaks, lighting and eye exams and why it is relevant professional knowledge, not just personal comfort.The journeyman's exam on data and communications educationCareer · 8 minData and Communication Education is a collective term for several related vocational qualifications, each concluded with a journeyman examination. The article covers how to choose between the IT support and data technician tracks, what the journeyman examination typically contains, and what paths open up after the journeyman certificate — including relevant certifications.