In William Shakespeare's tragic play Macbeth, the murder plot against King Duncan and Banquo are very different.
In regards to the murder plot against King Duncan, Lady Macbeth was responsible for creating the plan to take Duncan's life. While Lady Macbeth made the plot, Macbeth is responsible for carrying out the murder. This is seen in Act I, Scene V when lady Macbeth states that she has devised a plan:
and you shall put
This night's great business into my dispatch;
Which shall to all our nights and days to come
Give solely sovereign sway and masterdom. (lines 67-70)
Macbeth replies, after completing Lady Macbeth's plan in Act II, Scene ii, "I have done the deed."
Therefore, in the murder of Duncan, Lady Macbeth plans it and Macbeth carries it out.
In the plot to kill Banquo, Macbeth is the one responsible for the planning. When Macbeth tells Lady Macbeth that he will bring comfort to their castle, she asks him, "What's to be done?" Macbeth replies, "Be innocent of the knowledge, dearest chuck." Macbeth is taking full responsibility for the planning of Banquo's murder. While he is not the one who actually takes Banquo's life, he hires murderers, he is the one who plots the deed.
Therefore, the differences between the two murders lie with both the one who devises the plan and actually completes the murders. For Duncan's murder, Lady Macbeth devises the plan and Macbeth carries it out. For the murder of Banquo, Macbeth devises the plan and hired murderers carry out the murder.