Describe what is a J Curve?

What will be an ideal response?

The time lag with which real currency depreciation improves the current account. The current account is measured in terms of domestic output, and can drop quickly right after real currency depreciation because most import and export orders are placed several months in advance. In the first few months after the depreciation, export and import volumes therefore may reflect buying decisions that were made on the basis of the old real exchange rate.