The correct selector to target elements based on their class is .class. It is a fundamental selector in CSS for styling specific elements with a given class.

Dynamic programming is a technique used to solve problems by breaking them down into smaller overlapping subproblems, solving each subproblem only once, and storing the solutions for future use. It's particularly useful for optimization problems.

ETL stands for Extract, Transform, and Load. This process is fundamental in data migration, where data is extracted from a source, transformed as necessary, and then loaded into a target system.

Python is renowned for its simplicity, readability, and extensive standard library. It is commonly used in web development with frameworks like Flask and Django, making it a popular choice for building web applications.

Hoisting in JavaScript refers to the behavior where function declarations are moved to the top of the scope during compilation, allowing them to be used before they are declared.

The time complexity of accessing an element in an array is O(1) or constant time. This is because arrays provide direct access to any element using its index, and the access time remains constant regardless of the array size.

In Cassandra, the placement of data on nodes is determined by the Partition Key. It is crucial for distributing data across the cluster efficiently.

The WHERE clause in SQL is used to filter results based on a specified condition. It allows you to specify conditions that the data must meet to be included in the result set.

Session Hijacking involves an attacker stealing a user's session token and using it to impersonate the user. This attack allows unauthorized access to sensitive data.

Performance profiling involves analyzing a program's runtime behavior to identify bottlenecks and resource-heavy sections. It helps optimize code for better efficiency and speed.