A REST API (Representational State Transfer Application Programming Interface) is a set of rules and conventions for building and interacting with web services. It enables the requesting systems to access and manipulate web resources by using a uniform and predefined set of stateless operations. Here’s a breakdown of its main concepts and characteristics:

1. Representational State Transfer (REST): This is an architectural style that defines a set of constraints used for creating web services. Web services that conform to the REST architectural style, termed RESTful web services, provide interoperability between computer systems on the internet.

2. Statelessness: In the context of REST, statelessness means that each request from a client to a server must contain all the information needed to understand and complete the request. The server does not store any session information about the client. This makes the system more scalable and simpler to implement.

3. Resources: The key abstraction of information in REST is a resource. A resource is any piece of information that can be named, such as a document, an image, a temporal service (e.g., “today’s weather in Los Angeles”), a collection of other resources, a non-virtual object (e.g., a person), and so on. Resources are identified by URIs (Uniform Resource Identifiers), which provide a global addressing space for resource and service discovery.

4. HTTP Methods: REST uses standard HTTP methods to perform operations on resources. The most common HTTP methods are:

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Python and JavaScript are two of the most popular programming languages today, each with its own unique uses, capabilities, and characteristics. Here are some key differences between Python and JavaScript:

1. Intended Purposes and Domains of Application:

– Python: Known for its simplicity and readability, Python is a general-purpose programming language. It’s widely used for server-side web development, data analysis, artificial intelligence (AI), scientific computing, and more. Python’s comprehensive standard library supports a variety of applications, from web development frameworks (like Django and Flask) to scientific computing libraries (like NumPy, SciPy, and Pandas).

– JavaScript: Initially created for client-side web development, JavaScript is primarily used to make web pages interactive and dynamic. It runs in the web browser, allowing for the manipulation of webpage content and behavior in response to user actions. Over time, with technologies such as Node.js, JavaScript has expanded into server-side applications, mobile app development, and more.

2. Syntax and Design Philosophies:

– Python: Emphasizes readability and simplicity. Python code often reads like English, which makes it an excellent choice for beginners in programming. It uses indentation to define code blocks instead of curly braces or keywords, making the code clean and visually uncluttered.

– JavaScript: While also relatively straightforward, JavaScript’s syntax is more akin to that of other C-like languages. It uses curly braces to define blocks of

Recursion is a method in programming and mathematics where a function calls itself in order to solve a problem. At its core, recursion is a problem-solving technique that breaks down a problem into smaller instances of the same problem (subproblems) until it reaches instances that are simple enough to be solved directly. These solutions are then combined to solve the original, larger problem.

### How it works:

1. Base Case: This is a condition within the recursive function that does not lead to another recursive call. Instead, it produces a direct answer. The presence of a base case ensures that the recursion will eventually end, preventing an infinite loop of function calls.

2. Recursive Case: This involves the function calling itself with modified arguments. The idea is that each recursive call will bring the problem closer to the base case, gradually making the problem smaller or simpler.

### Example in Python:

To better understand recursion, let’s look at a classic example – calculating the factorial of a number, where the factorial of `n` (`n!`) is the product of all positive integers less than or equal to `n`.

def factorial(n):

# Base case: If n is 0 or 1, return 1 (since 0! = 1 and 1! = 1)

if n in [0, 1]:

return 1

# Recursive case: n! = n * (n-1)!

else:

return n *