An Embassy is a building or complex in a country that serves as a representative of another country. The embassy usually has representatives called "ambassadors" as they interact with the host country to resolve or mediate disputes and handle legal formalities for providing visas.
For example, The UAE has an embassy in India, and we also have a Indian Ambassador in UAE. As a rule, there is a group of workers and a guard stationed there, as well as any other embassy for security reasons.
Thus, when an individual look for job or study abroad he needs to meet certain requirements such as legalisation of documents and embassy attestation is one of the crucial attestation one amongst other attestations.
While embassy provide attestation for all types of documents such as personal, educational & commercial. Though embassy attestation is required only if the destination country of a traveller is not member of Hague Convention.