They look the same

The majority of the Indians are Hindu

The majority of the Bangladeshis are Muslim

The share the same culture

Bangladesh was earlier known as East Pakistan but in 1971 a war broke out between present day Bangladeshis & Pakistanis over Pakistan's terrorism supporting attitude & mass extermination of Bangladeshis in east Pakistan by Pakistani terror groups. Bangladeshis pleaded India to help them to which India ignored in the beginning but when millions of Bangladeshis started to migrate into India from both Pakistan & Bangladesh, India helped Bangladeshis to win their own country from Pakistan.

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Most Bangladeshis are Muslim.

Bangladeshis are descended from various groups, including indigenous peoples, Dravidian tribes, Indo-Aryans, Mughals, and Persians. The population is a mix of different ethnicities and cultures that have contributed to the diverse origins of present-day Bangladeshis.