Dollar-cost averaging is investing a fixed amount at regular intervals — monthly, say — regardless of what the price is doing.
Because the fixed amount buys more units when prices are low and fewer when they are high, it removes the need to judge timing. Historically, investing a lump sum all at once has produced better average outcomes, simply because the money spends longer invested. What averaging buys is not higher returns but a smaller chance of investing everything at a peak — and, more practically, a habit that people actually sustain.