SSIS Question:

Variable allows us to dynamically control the package at runtime. Example: You have some custom code or script that determines the query parameter’s value. Now, we cannot have fixed value for query parameter. In such scenarios, we can use variables and refer the variable to query parameter. We can use variables for like:
1. updating the properties at runtime,
2. populating the query parameter value at runtime,
3. used in script task,
4. Error handling logic and
5. With various looping logic.