To create a Synthetic Long you buy the Call and sell the Put at the same strike creating a synthetic long stock position.
As Martin says, you wouldn’t normally choose this simply to replicate holding the stock, but you'd utlise it if you were in a complex position and needed the equivalent such as for a hedge or if sufficient quantity of physical stock were unavailable (a situation that has rarely been a problem in reality or in the virtual world of naked short selling...).
The synthetic long has almost the same P&L potential as owning the stock outright. The Cons of a synthetic long is the premium you pay on the purchased Call and the loss of dividends on the stock ownership. The Pros of the synthetic long are the income of the premium on the sold Put, the lower overall investment required to control a much larger amount of stock and therefore, the interest opportunity on those funds not employed in the position.