How do people vote when they are away from their polling community?

Below

Explanation:

Voting at a different polling station

Among countries where voters are allocated to one or several specific polling station (such as the polling station closest to the voter's residential address, or polling stations within a particular district, province or state), some countries provide a mechanism by which voters can nevertheless cast their ballots on election day at a different polling station.

The reasons for allocating voters to specific polling stations are generally logistical. Absentee voting at a different polling station might be catered for by, for example, designating some larger polling stations as available for absentee voting, and equipping such polling stations with the ballot papers (or the means to produce ballot papers) applicable to an absentee voter.

In the electoral terminology of some countries, such as Australia, "absentee voting" means specifically a vote cast at a different polling station to one to which the voter has been allocated. "Early voting", "proxy voting" or "postal voting" are separate concepts in these countries.

When a person changes his residence, he needs to update the authorities and voter registration and then only he can cast his vote in the new location.

Explanation:

There is no concept of online voting therefore whenever a person is changing his or her residence, he is required to update the authorities regarding the same so that at the time of elections he can exercise his right to vote.

The polling place of an individual is based on his or her residential address and therefore he is required to cast vote at the assigned polling place. If a person cast his vote at any other polling place the n one which is assigned for him, his vote will not be counted.