Parameters variable could be defined in Parameter of request. it will help you to merge many requests to one and make API easy to maintain.

For example, we have a API: http://httpbin.org/get?boy={{boy}}&girl={{girl}}, there are two variables in this API. We can use Parameter and define it like this:

{
    "boy": ["tom", "jerry", "mike"],
    "girl": ["lucy", "lily", "cristina"]
}

We will get 3 requests with OneToOne option:

http://httpbin.org/get?boy=tom&girl=lucy
http://httpbin.org/get?boy=jerry&girl=lily
http://httpbin.org/get?boy=mike&girl=cristina

and get 9 requests with ManyToMany option:

http://httpbin.org/get?boy=tom&girl=lucy
http://httpbin.org/get?boy=tom&girl=lily
http://httpbin.org/get?boy=tom&girl=cristina
http://httpbin.org/get?boy=jerry&girl=lucy
http://httpbin.org/get?boy=jerry&girl=lily
http://httpbin.org/get?boy=jerry&girl=cristina
http://httpbin.org/get?boy=mike&girl=lucy
http://httpbin.org/get?boy=mike&girl=lily
http://httpbin.org/get?boy=mike&girl=cristina

All these APIs are in a Request.

We can send all at a time or select one and send.