They have the same meaning, they change because of grammar. 'I do,' 'He does,' and so on. Here's a table:
I Do
You Do
He/she/it Does
We Do
You (plural) Do
They Do
As you can see, we can only use 'does' if the word before it is 'he,' 'she' or 'it.' For example 'He does like you.' 'She does this for a living.' 'It does work!'
If there is a word inbetween he/she/it and 'does,' then we cannot use 'does' - we must use 'do.' For example, 'He cannot do it.' 'He must do this.' 'She will do it.'
I hope that helps! Good luck with learning English. You can do it! :)