If you need some advanced explanation you need read both specifications :
https://oauth.net/core/1.0a/
https://oauth.net/2/
If you need a clear explanation of flow differences , this could be help you:
OAuth 1.0 Flow
- Client application registers with provider, such as Twitter.
- Twitter provides client with a “consumer secret” unique to that application.
- Client app signs all OAuth requests to Twitter with its unique “consumer secret.”
- If any of the OAuth request is malformed, missing data, or signed improperly, the request will be rejected.
OAuth 2.0 Flow
- Client application registers with provider, such as Twitter.
- Twitter provides client with a “client secret” unique to that application.
- Client application includes “client secret” with every request commonly as http header.
- If any of the OAuth request is malformed, missing data, or contains the wrong secret, the request will be rejected.
Source : https://codiscope.com/oauth-2-0-vs-oauth-1-0/