Explanation
Based on the following code, the variable type of connection_full is a structure. A structure is a complex data type that consists of a group of related data objects, called components, that have their own data types and names. A structure can be defined using the TYPES statement or based on an existing structure type, such as a CDS view entity or a CDS DDIC-based view. In this case, the variable connection_full is declared using the TYPE addition, which means that it has the same structure type as the CDS view entity /DMO/I_Connection.
The CDS view entity /DMO/I_Connection is a data model view that defines a data model based on the database table /DMO/Connection. The CDS view entity /DMO/I_Connection has the following components:
carrid, connid, airpfrom, airpto, distance, and fltime. Therefore, the variable connection_full has the same components as the CDS view entity /DMO/I_Connection, and each component has the same data type and length as the corresponding field in the database table /DMO/Connection.
References: CDS Data Model Views - ABAP Keyword Documentation, DATA - ABAP Keyword Documentation, Structure Types - ABAP Keyword Documentation