The files are structured in a way for it to be easily tested using truffle. The smart contract is written in solidity whereas the migration and test code is written in javascript. The samrt contract enables the one who submits it to propose something. This proposal can then be voted. This vote has a predetermined end date and only wallets above the predetermined minimum balance can participate in it. The votes can be tallied even during the voting process. The only purpose of the smart contract is to count the votes not to execute something depending on the results.