What part of the bicep do wide grip barbell curls and close grip

What are the best dumbell bicep exercises for muscle? close grip or wide for barbell curls?

A wide grip places more emphasis on the short head of the biceps brachiis.
Wide-grip barbell curls allow you to use more weight and stress the short (inner) head of the biceps more.

One of the best ways to isolate the biceps when doing particular work out that includes your arms is to perform the close grip barbell curl.

 

Here’s a video to assist you on the Close Grip Barbell Curl: