Explain the concept of synchronous execution of tasks and its features.

Synchronous execution of tasks means that tasks are performed sequentially, one after another, and the next task does not start until the current one finishes. In iOS, this is often encountered when calling functions that block the thread until a result is obtained.

Features of synchronous execution:

• The execution thread is blocked until the task completes.
• Convenient for simple operations where you need to wait for a result.
• Can lead to UI blocking if a long-running task is performed on the main thread.

Example:

func fetchData() {
    let data = loadDataSynchronously() // blocks the thread until completion
    print(data)
}

Here, the loadDataSynchronously function will not return control until it receives data, which can freeze the UI if called on the main thread.