DCA (dollar/euro cost averaging) means always investing the same amount on a regular basis — for example, €200 a month — instead of trying to pick the best moment to invest a lump sum all at once.
What it achieves
By always buying the same amount in euros, you buy more units when the price is low and fewer when it's high, which smooths out your average purchase price and reduces the risk of investing everything right before a drop.
It doesn't maximize returns, it reduces risk
Statistically, investing the entire capital at once (lump sum) tends to beat DCA in long-term bull markets. The real value of DCA is psychological and about risk management: it automates discipline and avoids emotional "market timing" decisions.