Yes- justify-content: center will center items along the flex direction. For example, if your flex-direction is "row" then it will center your items in the middle of the row horizontally. align-items: center will center your items in the middle of the row vertically.
For example, justify-content: center and flex-direction: row centers items the same as align-items: center and flex-direction: column
For example, justify-content: center and flex-direction: row centers items the same as align-items: center and flex-direction: column