What forms when an acid and base form?

The pH changes. An acid is anything 7.1 or greater on the pH scale. A base is 6.9 or less. 100% pure water is completely neutral at 7.0

(below is by Chew Jian Yue)
Base is definitely an alkaline.
When acid and alkaline reacts in chemistry, it will form a salt and water.
For example, Hydrocloric acid reacting with sodium hydroxide will form a salt which is Sodium Chloride and Water.