HTML Definition HTML is the standard markup language for Web pages HTML is NOT a programming language HTML Elements Header 1 2 <h1> header1</h1> <h2> header2</h2> Paragraph <p>Text here</p> Change text fonts: 1 2 3 <i>Italic</i> <u>Underline</u> <b>Bold</b> Section 1 2 3 <section> elements... </section> Lists 1 2 3 4 5 6 7 8 9 10 11 Unordered list <ul> <li> Apple </li> <li> Banana </li> </ul> Ordered list <ol> <li> Apple </li> <li> Banana </li> </ol> Links 1 <a href="index.

SQL queries SQL Summary: https://www.w3schools.com/sql/sql_examples.asp SQL operations: https://www.w3schools.com/sql/sql_operators.asp Select 1 2 3 4 select column from table select distinct column from table select distinct id from table Where 1 2 3 4 5 SELECT * FROM Customers WHERE Country='Mexico' SELECT * FROM Customers WHERE CustomerID=1 AND, OR and NOT Operators 1 2 3 4 5 SELECT * FROM Customers WHERE Country='Germany' AND (City='Berlin' OR City='München'); SELECT * FROM Customers WHERE NOT Country='Germany' AND NOT Country='USA'; ORDER BY This means that it orders by Country, but if some rows have the same Country, it orders them by CustomerName in descending order:

Different Testing Concepts Unit testing: test the smallest piece of code Integration testing: test if different components work together System testing: test every component of an application to make sure that they work as a complete and unified whole Smoke testing: ensure that the critical functions of the program are working Regression testing: determine if code modifications break an application Performance testing: examines the speed, stability, reliability, scalability, and resource usage of a software application under a specified workload Load testing: determines how the software application behaves while being accessed by multiple users simultaneously Stress testing: tests beyond normal operational capacity to test the results More White box testing: Know code and structure of the product to be tested and uses that knowledge to perform the tests Black box testing: Does not know its internal functioning

Multithreading on a Single Processor The execution of multiple threads on a single CPU Multithreading on a single processor gives the illusion of running in parallel. In reality, the processor is switching by using a scheduling algorithm. Or, it’s switching based on a combination of external inputs (interrupts) and how the threads have been prioritized. These threads run concurrently and they share resources For example, this is a bit like chatting with different people through various IM windows; although you’re actually switching back and forth, the net result is that you’re having multiple conversations at the same time.

Concurrency (Multithreading on a Single Processor) Concurrency means executing multiple tasks at the same time but not necessarily simultaneously. When you have to perform more than one task but you have a single resource then we go for concurrency. In a single-core environment, concurrency is achieved by context switching. (the execution of multiple tasks is interleaved, instead of each task being executed sequentially one after another.) For example: This is a bit like chatting with different people through various IM windows; although you’re actually switching back and forth, the net result is that you’re having multiple conversations at the same time.

What is a Thread, really? Short answer: Thread is a subset of a process Longer answer: Thread is an independent set of values for CPU registers Detailed answer: A thread is an execution context for CPU, which is all the information CPU needs to execute instructions. Essentially: More about thread Thread components: Program counter: keeps track of which instruc­tion to execute next Stack: which contains the execution history Registers: which hold its current working variables Example: A single thread could be displaying the current tab you’re in, and a different thread could be another tab.