Glossary

Authentication vs Authorization

Authentication	Authorization
Identifies the person or service seeking access to a resource	Determines an authenticated person's or service's level of access
Requests legitimate access credentials	Defines which data they can access, and what they can do with it.

Data Processing

a process of conversion of raw data to meaningful information.

Batch Processing	Stream Processing
A process in which multiple data records are collected and stored before being processed together in a single operation.	A process in which source of data is constantly monitored and processed in real time as new data event occurs.
Example - Credit card companies handling billing. The customer doesn't receive a bill for each separate credit card purchase but one monthly bill for all of that month's purchases.	Example - A financial institution tracks changes in the stock market in real time, computes value-at-risk, and automatically rebalances portfolios based on stock price movements. An online gaming company collects real-time data about player-game interactions, and feeds the data into its gaming platform. It then analyzes the data in real time, offers incentives and dynamic experiences to engage its players.

Dependency Injection Pattern

The Dependency Injection pattern uses an object (the container) to initialize objects and provide the required dependencies to the object.

Web Services

AJAX - Asynchronous JavaScript And XML

REST API - Representational State Transfer API

Web API

Spark uses lazy evaluation; that means it will not do any work, unless it really has to. That approach allows us to avoid unnecessary memory usage, thus making us able to work with big data.

Performance Optimization

• Focus on bottlenecks first

• Reduce the number of round trips

• Parallelize external calls

• Caching

Shell

• Windows - PowerShell (treats the output as objects)

• macOS - ZShell (a unix shell that extends Bourne-again Shell (BASH shell) functionality)

• BASH follows the language and syntax called the Shell Command Language as defined by POSIX.

ZSH treats the output as strings such as writing to .txt files.