Go Ethereum is an open-source tool developed by the Etherium community. It is built over Google’s Go language, C++, and Python. Since Geth is open-source, anyone can contribute through its GitHub. Till now, 423 people have contributed code to Go Ethereum. Go Ethereum is available as Geth that helps to do transactions with smart contracts on the Ethereum blockchain.
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You can watch this video on what is Ethereum to get an overview of Ethereum: