Notes, summaries, assignments, exams, and problems for Computers

Computer Fundamentals and Data

A Computer is a programmable electronic device that can store, retrieve, and process data.

Data and Instructions: Instructions that manipulate data are logically the same as the data itself and can be stored in the same memory location.

Understanding Machine Language

Machine Language is a language made up of binary-coded instructions built directly into the computer's hardware and used by the processor.

Why Machine Language?

It is the fundamental language the hardware understands (no choice).

Characteristics of Machine Language

• Every processor has its own unique set of machine instructions.
• The relationship between the processor and the instructions it can carry out is completely integrated.
• Each machine-language instruction

Web Design & Development

Common Terms

Web Design

Is the act or practice of determining how a website looks.

Web Development

Is the act or practice of determining how a website works.

Navigation

Is the act of using and finding things on a website.

CSS

(Cascading Style Sheets) is a simple language that decides how a web page looks.

Coding

Is the programming language that makes up a website.

Visibility

Is how easily people find a website using search engines, based on how many other websites link to it.

Usability

Is how easy it is for a person to use a website.

Content

Is the material on a web page, including text and graphics.

Appearance

Is how a web page looks.

Functionality

Is the ability of different elements of a website to work together.

Programming Languages

C

Is... Continue reading "Web Design & Development Glossary: Terms and Definitions" »

Understanding Data, Processing, and System Components

1. Data Input and Storage

   Text, numbers, graphics, videos, and sounds entered into a computer's memory during input operations are referred to as ________.

   Data

2. Information Output

   Data that has been processed and converted into information is known as ________.

   Output

3. High-Capacity Computing Systems

   A ________ is a computer found in large businesses, organizations, and government agencies where thousands of users must simultaneously use the data and resources of their institution.

   Mainframe

4. Example of an Input Device

   A ________ is an example of an input device.

   Keyboard

5. Converting Physical to Digital Files

   A ________ is a device that converts documents or photos into digital files so they can be saved on

Chapter 3: Statelessness

This means that each request from a service consumer should contain all the necessary information for the service to understand the meaning of the request. All session state data should then be returned to the service consumer at the end of each request.

Figure 5.2. Statelessness ensures that each service consumer request can be treated independently by the service.

1. Cookies: Temporary data stored on the client-side, encrypted if SSL is used.

2. Types of Certificates:

• Site
• Personal
• Software Vendor
• Anonymous

3. Identity: Used for:

• Authentication
• Accountability
• Identifying principle

4. Principal: A unique identity. Identity is used to identify the principal, which is a computer representation of an entity.

5. Goals of a Certificate Regarding Identity: To bind the correct identity to a distinguished name.

6. Malicious Logic: A set of instructions that cause a site's security policy to be violated.

7. Predictable Computer Usage Patterns: Yes, my usage is statistically predictable. I often work from home, so the patterns between work and home are similar. I check email, run the browser, run Visual Studio, NetBeans, a... Continue reading "Security Essentials: Certificates, Identity, and Access Control" »

To start a backend project.

- npm init

Then make a file with whatever entry point you named it as, for example, server.js

Once package.json is created:

• npm i <package>
• connect-mongo (store sessions in DB)
• dotenv (for config files, environment variables)
• express
• mongoose
• express-sessions (sessions and cookies)
• method-override (to use PUT, UPDATE, DELETE requests)
• moments (date formatting)
• morgan (logging)
• passport (authentication)

npm i -D <package>

• nodemon (Update every file change instantly without having to restart the server)
• cross-env (To update environment variables in script definition itself)

After installing the dependencies, edit the scripts in package.json

Instructions:

1. Refer to the files using a relative path.
2. Save all files, including the HTML file, before using this feature.

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Understanding Algorithms

A programming algorithm is a computer procedure, much like a recipe, that tells your computer precisely what steps to take to solve a problem or reach a goal.

Evolution of Data Management

Early data management systems include file and database systems that were designed prior to the relational database in the 1970s. These include:

• Flat File Data Management
• Hierarchical Data Management Systems
• Network Data Management Systems

Database Generations & Models

1. Flat File Data Model

An organized set of data stored in a long-term storage medium, such as a disk or magnetic tape.

2. Hierarchical Data Model

Files are related in a parent/child manner, with each child file having at most one parent file.

3. Network Data Model

Made of data... Continue reading "Data Management Fundamentals: Databases, Algorithms, & Distributed Systems" »

Firewalls lay the foundation for network security. One of the most effective steps an organization can take to ensure network security is to install firewalls. A firewall can effectively enforce general security guidelines, such as disallowing audio streaming, controlling Internet access, or providing a virtual blockade from unknown network traffic. A firewall can be implemented as a software application or a hardware device and is designed to handle a number of crucial security tasks:

• Firewalls restrict network traffic between networks.
• Firewalls provide a chokepoint—a single point of entry or exit.
• Firewalls can record network activity.

Because firewalls play such an important role within a network and are usually placed in the most vulnerable... Continue reading "Understanding Firewalls: Essential for Network Security" »

Types definition

#include <stdbool.h>

#include <stdlib.h>

Struct Definition

typedef int tItemL;
typedef struct tNode* tPosL; //Ptr to tNode
struct tNode {
tItemL data;
tPosL next;
tPosL prev;
};
typedef tPosL tList;

Prototypes

void createEmptyList(tList *L);
bool createNode(tPosL* p);
bool insertItem(tItemL d, tPosL p, tList *L);
void updateItem(tItemL d, tPosL p, tList* L);
tPosL findItem(tItemL d,tList L);
bool isEmptyList(tList L);
tItemL getItem(tPosL p, tList L);
tPosL first(tList L);
tPosL last(tList L);
tPosL previous(tPosL p, tList L);
tPosL next(tPosL p,tList L);
void deleteAtPosition(tPosL p , tList *L);
void deleteList(tList *L);

Function Definitions

#include "doubly_linked_list.h"
bool isEmptyList(tList L) { return (L == NULL); }
void... Continue reading "Doubly Linked List Implementation in C" »