The N1QL query language, used for querying and managing data in Couchbase, is designed to be flexible and powerful. While its syntax can be limited, it offers unlimited query possibilities. Understanding the default execution flow of a query is essential, as it can significantly impact performance. The query plan structure and data flow can be visualized using the built-in `visual explain` feature, which provides an interactive way to understand the order of execution and optimize for performance by creating indexes. By analyzing the query plan, developers can identify areas where optimization is needed, such as reducing the number of scans or minimizing the amount of work done by each operator.