Final answer:
Cyclomatic complexity measures program complexity, while fan-in and fan-out measure interconnectivity of software modules or components.
Step-by-step explanation:
Cyclomatic complexity is a software metric used to measure the complexity of a program by counting the number of linearly independent paths through its source code. It helps in identifying the number of test cases needed to achieve a certain level of coverage.
On the other hand, fan-in and fan-out are metrics used to measure the interconnectivity of modules or components within a software system. Fan-in refers to the number of modules or components that call a particular module or component, while fan-out refers to the number of modules or components called by a particular module or component.
In terms of effectiveness, cyclomatic complexity can help identify areas of code that are more complex and may require additional testing or refactoring. A higher cyclomatic complexity suggests increased complexity and potentially greater risk. On the other hand, fan-in and fan-out can provide insights into the level of dependency and coupling between modules, which can impact maintainability and understandability of the software system.