Lesson 1: The Active Explorer, Digital Communication Tools and Computer Networks

• Describe how research and field exploration methods changed with digital technology.
• Use positioning and surveying tools to record a field site, and explain what each instrument adds.
• Distinguish a public network from a private one and justify the choice of media for a given installation.
• Evaluate the risks and the benefits of connected devices and cloud services.

• Computer network: two or more computers linked to exchange messages and share peripheral devices such as printers and central storage units.
• Internet: the public open global network connecting billions of users.
• Intranet: a private closed network restricted to one organisation, reachable only with authorisation.
• IoT (Internet of Things): extending the Internet from computers and phones to everyday objects fitted with sensors and connectivity.
• Cloud computing: storing files and running software on giant remote servers reached through the Internet instead of local hardware.
• GPS: a satellite system that fixes the position of a device anywhere on Earth.

• The modern explorer no longer relies on paper maps and a traditional compass only; he carries an integrated technology kit that raises the accuracy and the speed of field work.
• GPS: locates archaeological and environmental sites and traces exploration routes with great precision, and records the coordinates for later mapping.
• Geographic information systems (GIS) and digital maps: store the collected locations as layers, so terrain, findings and routes can be analysed together.
• Field sensors and mobile applications: measure temperature, humidity and altitude, and log observations instantly in a shared database instead of a paper notebook.
• Drones fitted with high-resolution cameras and thermal sensors: photograph rough terrain such as mountains, forests and desert valleys and run a complete aerial topographic survey that saves time and effort and keeps the team out of danger.

• A network links computers so that messages, information and devices (printers, central storage) are shared.
• Networks are classified by geographic coverage:

Classes by coverage

• LAN (Local Area Network): covers a small limited area, is very fast, has a high data-transfer rate, and is easy to manage and to secure — a school lab or an office floor.
• MAN (Metropolitan Area Network): connects several networks inside one city.
• WAN (Wide Area Network): spans large distances through communication lines, satellites and submarine fibre-optic cables — the Internet itself is the largest WAN.

• The Internet is public and open: it links billions of users worldwide, anyone may reach it and browse its content, and access is unrestricted.
• An intranet is a private local network closed to a specific institution — a school or a bank — and exists mainly to protect the institution's data; outsiders cannot enter without encrypted security clearance.
• Comparison to memorise: openness (public / private), audience (everyone / members of one organisation), security requirement (external protection / internal access control), and typical use (research and communication / internal documents and services).
• An intranet may use Internet technologies (browsers and web pages) while remaining closed — the two are not opposites in technology, only in access.

• Wired: fibre-optic cables carry light signals at very high speed over long distances with little loss and no electrical interference; twisted-pair Ethernet cables are cheaper and easy to install over short distances.
• Wireless: Wi-Fi and radio links, Bluetooth for very short ranges, and satellite links for remote areas where cabling is impossible.
• Choosing the medium depends on distance, required speed, budget and the environment — a factory floor with electrical noise favours fibre, a mobile classroom favours Wi-Fi.

• IoT is one of the greatest revolutions of modern technology: the Internet is no longer limited to computers and phones but connects everyday objects and appliances, each with sensors that collect data and exchange it automatically.
• Examples: smart homes that control lighting and air conditioning, sensors that irrigate farmland only when the soil is dry, wearables that track pulse and activity, and smart cities that manage traffic and street lighting.
• IoT also supports people of determination and those with special needs: smart prosthetic limbs, Internet-connected wheelchairs, screen-reading software and personal digital assistants.
• Its risks are the price of its benefit: every connected object is a possible entry point, so weak passwords, un-updated firmware and mass data collection become security and privacy threats.

• Cloud computing lets users store and retrieve digital files and run complex software on giant Internet-connected servers (for example Google Drive) instead of a local hard disk.
• Benefits: access from any device anywhere, no need to buy large hardware, automatic backup and recovery, easy sharing, and pay-as-you-use cost.
• Limitations: the service needs an Internet connection, speed depends on the provider, and the data is held by a third party — so sensitive files must be encrypted and the provider's terms read.
• Syncing versus uploading: sync keeps a live two-way copy on every device, while an upload is a one-time transfer.

• Digital communication gives an ideal environment for school projects and group research, letting team members coordinate and finish tasks through a range of tools.
• Communication: e-mail for formal messages and files, instant messaging and chat for quick coordination, and video conferencing for remote meetings with screen sharing.
• Collaboration: shared cloud documents and collaborative spreadsheets allow several students to write and edit at the same time, with revision history.
• Project management: task boards that distribute roles, set deadlines and follow progress; calendars and reminders keep the team on schedule.
• Evaluate a tool by: number of users, need for an account, real-time editing, storage capacity, cost, and privacy of the shared data.

• "A school wants a network inside one building for its teachers only, with fast file sharing and no outside access." → a LAN used as an intranet: small coverage (LAN) and closed membership (intranet); the justification quotes both speed and data protection.
• "An expedition must survey a rugged desert valley without putting the team at risk." → drones with high-resolution and thermal cameras for an aerial topographic survey, positions fixed by GPS.
• "Four students in different cities prepare one report together." → a shared cloud document with real-time editing, video conferencing for meetings, and a task board for assigning parts and deadlines.
• "A factory needs to link two halls 800 m apart in a hall full of electrical machinery." → fibre-optic cable: high speed, long distance and immunity to electromagnetic interference.

• Learn the definition of a network as "linking two or more computers to exchange messages and share devices" — the examiner looks for both parts.
• In the Internet/Intranet comparison write public-and-open versus private-and-closed, then give one example of each.
• IoT answers should pair a benefit with a risk; assistive technology for people of determination is the expected application.
• Cloud computing is defined by access over the Internet without heavy local hardware, not by "a very big hard disk".
• Transmission media: fibre = light signals and interference immunity; Ethernet = cheap and short range; wireless = mobility and difficult terrain.