A memory array comprising strings of memory cells comprises a conductor tier comprising conductor material. The memory array comprises laterally-spaced memory blocks individually comprising a vertical stack comprising alternating insulative tiers and conductive tiers directly above the conductor tier. Conducting material of a lowest of the conductive tiers is directly against the conductor material of the conductor tier. Channel-material strings of memory cells extend through the insulative tiers and the conductive tiers. Intervening material is laterally-between and longitudinally-along immediately-laterally-adjacent of the memory blocks. The conducting material in the lowest conductive tier is directly against the channel material of individual of the channel-material strings. Conductive material is of different composition from that of the conducting material above and directly against the conducting material. Other embodiments, including method, are disclosed.