Is 1er cru better than Grand Cru?

Could you please clarify for me the distinction between 1er cru and Grand Cru in the context of wine classification? Is it accurate to say that 1er cru is inherently superior to Grand Cru, or is it more of a matter of personal preference and the specific characteristics of each wine? Are there any notable differences in terms of taste, aroma, and aging potential between the two? Additionally, do these classifications differ significantly across different wine regions and grape varieties? I'm eager to gain a deeper understanding of these nuances in wine appreciation.