Decoded: Entire Nation Votes Through EVMs But Do You Know What Is VVPAT, Ballot Unit And Control Unit?

The voting for the first phase of the Lok Sabha Elections 2024 is underway across 21 states. This comes days after the Supreme Court reserved its verdict in a case related to EVM and VVPATs. While the Supreme Court has quashed the request for returning to the ballot paper regime, it has said that one should have some trust in the existing system of the EVM. The court, however, indicated the need for reforms in the current system.  The opposition parties in India have always been questioning the Electronic Voting Machines' credibility. However, during the hearing in the Supreme Court, the Election Commission of India revealed some crucial facts that are must for the common people to know:

What Is EVM?

EVM has three components - Ballot units, control units and Voter Verifiable Paper Audit Trail (VVPT). Together, these machines make a system which allows voters to vote and verify if their votes have been cast correctly. These units are joined together by a cable. 

What Is A Ballot Unit?

The ballot unit is a device on which political parties/candidates' symbols are pasted beside the button. An elector presses the button adjoining his/her choice of candidates to cast his/her votes. The ballot unit and VVPAT is kept in the voting compartment for the voters to use and verify.

What Is A Control Unit?

In simple language, it's the control unit that enables the Ballot Unit to accept votes from the voter and stores the votes cast. The control unit also sends a signal to VVPAT to print the symbol for whose button is pressed on the ballot unit. The control unit remains with the presiding officer at the booth.

What Is VVPAT?

The VVPAT is nothing but just a printer with 4 MB flash memory in which poll symbols are stored in an image format to allow printing of the symbols when a vote is cast. 

The ECI has informed the court that even the EVM maker doesn't know which button will be assigned to which political party or candidate. Even the machines are randomly selected for sending to different booths. The ECI also told the court that the voting machines run on firmware and the program cannot be changed.