difference questions

Static Site Generation (SSG) in Next.js generates HTML at build time, resulting in fast, static pages. Server-Side Rendering (SSR) generates HTML on each request, providing up-to-date content. SSG is ideal for content that doesn't change frequently, while SSR is better for dynamic content that needs to reflect real-time data.

In Next.js, static routes are defined by creating files in the `pages` directory, each representing a specific route. Dynamic routes are created by using square brackets in the file name (e.g., `[id].js`), allowing the route to match any value. Static routes are used for fixed paths, while dynamic routes handle variable segments.

The DATEDIF function calculates the difference between two dates based on a specified unit. For example, =DATEDIF(A1, B1, 'D') returns the number of days between the dates in A1 and B1. You can also use 'M' for months or 'Y' for years. This function is useful for calculating age, tenure, or duration.

In Vue.js, `v-if` and `v-show` are both used for conditional rendering, but they work differently. `v-if` adds or removes elements from the DOM based on the condition, making it suitable for cases where elements are toggled rarely. In contrast, `v-show` toggles the `display` CSS property of the element, keeping it in the DOM but hiding it from view. `v-show` is more performant for frequently toggled elements since it avoids the cost of re-rendering, while `v-if` is more efficient for infrequent toggling.

Synchronous methods block the event loop until the operation is complete, while asynchronous methods allow the program to continue running while the operation completes in the background. Example: fs.readFileSync is synchronous, while fs.readFile is asynchronous, not blocking the event loop.

Hashing is a one-way function that transforms data into a fixed-size string, making it irreversible, while encryption is reversible, allowing the original data to be retrieved with a key. BcryptJS uses hashing to securely store passwords, ensuring they cannot be easily decrypted.

Both malloc() and calloc() are used for dynamic memory allocation in C. malloc() allocates a block of memory without initializing it, whereas calloc() allocates and initializes memory to zero. calloc() also takes two arguments (number of blocks, size of each), while malloc() takes one (total memory size). 
 
int *arr = malloc(5 * sizeof(int));
int *arr2 = calloc(5, sizeof(int));

The .xls format is a binary file format used by Excel 97-2003, whereas .xlsx is an XML-based format introduced in Excel 2007. The .xlsx format allows for larger files and enhanced features like improved data recovery and better compression. For example, .xlsx files typically use less disk space.

'Layer Group' is a logical grouping of layers, while 'Layer Set' is a physical grouping, allowing for nested groups and organization.