P2P vs Client–Server
Apps & Protocols
Network Devices
Physical Topologies
OSI & Safety
100

In this model, devices share directly with each other without a dedicated central server.

What is peer-to-peer (P2P)?

100

The protocol that turns a website name like “youtube.com” into an IP address.

What is DNS?

100

This device connects your home network to your ISP (cable/fiber/DSL) to bring internet into the building.

What is a modem?

100

Most common modern wired layout: all devices connect to one central switch/router.

What is a star topology?

100

OSI Layer 1: deals with signals, cables, radio waves, connectors.

What is the Physical layer?

200

In this model, your phone requests content from a central system that controls access and stores data.

What is client–server?

200

The secure protocol used by most websites and apps for encrypted traffic.

What is HTTPS?

200

This device directs traffic between your home network and the internet; often your “default gateway.”

What is a router?

200

A topology where devices share one main cable; if the main line fails, many devices are affected.

What is a bus topology?

200

OSI Layer 3: responsible for routing packets using IP addresses.

What is the Network layer?

300

AirDrop/Nearby Share is most like this model because devices connect directly to exchange files.

What is peer-to-peer (P2P)

300

This protocol automatically assigns your device an IP address when you join Wi-Fi.

What is DHCP?

300

This device connects many wired devices on the same LAN and forwards traffic using MAC addresses.

What is a switch?

300

A topology where devices form a loop; a single break can cause problems unless there’s redundancy.

What is a ring topology?

300

OSI Layer 4: uses ports and decides between reliable vs fast delivery (TCP vs UDP).

What is the Transport layer?

400

TikTok/Instagram feeds rely on this model because content is stored and delivered from company servers.

What is client–server

400

This transport protocol is faster and often used for gaming/voice because it doesn’t guarantee delivery.

What is UDP?

400

This device provides Wi-Fi coverage so phones/laptops can connect to the network.

What is an access point (AP)?

400

Common in home “mesh Wi-Fi” systems: multiple nodes connect with multiple paths for resilience.

What is a mesh topology?

400

Best practice: enabling this adds a second step to login, reducing account takeover risk.

What is multi-factor authentication (MFA)?

500

One major downside of client–server networks: if this central component goes down, everyone can be affected.

What is the server (central server)?

500

This email protocol is used to send mail out from a client to a mail server.

What is SMTP?

500

This security device filters traffic based on rules to block threats and control access.

What is a firewall?

500

Most real networks combine multiple topologies (wired star + wireless coverage), known as this.

What is a hybrid topology?

500

Safety rule: you should only scan/test networks when you have this, otherwise it can become a policy/legal issue.

What is authorization/permission?