You can THINK of alignItems as justifyContent behaviour for cross axis. Cross-axis in case if React native is the horizontal axis. CSS alignItems property sets the alignSelf value on all direct CHILDREN as a group. In Flexbox, it controls the alignment of items on the cross axis. By default, the cross axis is a horizontal axis in case of React native. We can use this property to layout elements in the flex container. The alignItems property supports following VALUES: stretch|center|flex-start|flex-end|baseline|initial|inherit;  Let me explain alignItems values:

• flex-start: this is the default value for alignItems. It means that flex items will start from the left and evenly distributed horizontally.
• Flex-end: this is just the opposite behaviour of flex-start. Elements start rendering from the RIGHT and go up to the left end.
• Center: Items will be placed in the middle
• Space-between: elements are evenly distributed along the cross axis (horizontal  axis)
• Space-around: flex items will be evenly distributed with equal space around them