A sequence is an element that will automatically store customer orders consecutively by order number every time a new order is placed. A sequence is a database object that generates sequential numbers according to a specified rule. A sequence can be used to create unique identifiers for records in a table, such as order numbers or customer IDs. A vector is an element that can store multiple values of the same data type in an ordered sequence, but it does not automatically generate sequential numbers. A vector is a data structure that can be used in programming languages such as C++ or Java. An array is an element that can store multiple values of the same data type in an indexed sequence, but it does not automatically generate sequential numbers. An array is a data structure that can be used in programming languages such as C or Python. A constant is an element that can store a single value of any data type that does not change during the execution of a program, but it does not automatically generate sequential numbers. A constant is a variable that can be used in programming languages such as C# or JavaScript. References: The Official CompTIA IT Fundamentals (ITF+) Student Guide (Exam FC0-U61), Chapter 6: Database Fundamentals, Chapter 8: Software Development Concepts