Networks and Databases: CS101 Quiz 2 PDF

Networks → IPv4, uses 32-bits to 4 groups → IPv6, uses 128 bits to 16 parts e.g. A8FB:7A88:FFF0:0FFF:3D21:2085:66FB:F0FA → Subnetting: divide a network to smaller networks → URL: an easy way to access pages instead of using IP addresses. →DNS: contain database of URLs and their matching IP ad...

Networks → IPv4, uses 32-bits to 4 groups → IPv6, uses 128 bits to 16 parts e.g. A8FB:7A88:FFF0:0FFF:3D21:2085:66FB:F0FA → Subnetting: divide a network to smaller networks → URL: an easy way to access pages instead of using IP addresses. →DNS: contain database of URLs and their matching IP addresses. Meaning:- When a user enters a URL: The DNS searches the database for the URL and translate it to IP. It then communicates with the internet to fetch the page requested. → To reduce the need for many IPs, we divide the internet to a series of private networks. → Components of Network: Hardware: Router, Cables, LAN Cards Protocols: IP, DSL Software: Firewalls, Network back-end management →Connection models: Client-Server Model & Peer-To-Peer Model i. Client- Server Model: Data is managed and distributed by the central server. Back-ups are consistent and done by the server.  ii. Peer-To-Peer Model No Central Server. Nodes (peers) share data directly. e.g. Bluetooth → Shapes and Toplogies : Bus Toplogy, Star Topology, Mesh Toplogy, Hybrid Topology →Network Hardware: Router, Hub, Switch  DATABASES PRIMARY KEY: EMPLOYEE_ID and JOB_CODE COMPOSITE KEYS (two primary keys) → DBMS (DataBase Management System) , SQL (Structured Query Language) →Data Redundancy: Stores data in linked tables, so no repetition is needed. → Data Inconsistency: Data is stored mostly once, so hard to make it inconsistent. CREATE DATABASE database_name-> creates a database CREATE TABLE table_name-> creates table PRIMARY KEY: set attribute as primary key FOREIGN KEY: set attribute as foreign key. ALTER TABLE: modifies the table. SELECT column name FROM table_name WHERE condition ORDER BY → returns data in ascending or descending order INNER JOIN column-name ON Column-Name→ join two rows with common column SUM, COUNT, MAX, MIN, AVG  HTML ✓HTML stands for Hyper Text Markup Language ✓HTML is the standard markup language for creating Web pages Paragraph is here Page Title begining and ending of code this is heading 1 largest size Heading 2 Heading 3 Heading 4 Heading 5 Heading 6 smallest size Font This is a heading This is a paragraph. This is a heading Alignment Centered Heading Centered paragraph. Color With HTML ,RGB colour values can be specified using this formula: (red, green, blue) (255,0,0) Hello World Lorem ipsum... Hyperlink: HTML links are hyperlinks, when you click on a link and jump to another document. link text → How to view HTML source? i. Click CTRL + U in HTML page, OR right-click on page and select “View page source” ii. Right-click on an element (or a blank area), and choose "Inspect" to see what elements are made up of (you will see both the HTML and the CSS) Internal Styling is used to define a style for one HTML page. It is defined in the section with a element. External Styling is used to define the style for many pages, by adding a link in the section HTML image syntax : src → specifies the path to the image alt→ specifies an alternate text for the image HTML table Tables are defined with the tag Tables are divided into table rows with the tag Table rows are divided into table data with the tag. Table row can also be divided into table headings with the tag. To make a cell span over multiple columns, use the colspan attribute: To make a cell span over multiple rows, use the rowspan attribute: