Which means you also know that ‘when the carboxylate is long chain, its salt is called a soap’. And that the esters in question are oils and fats, and the aqueous alkali is traditionally lye, or caustic soda.
As our learned friend Dr Wikipedia continues to explain, the lye ‘cleaves the ester bonds’. This is an unwittingly apposite turn of phrase, since ‘cleave’ is one of those chimeric contranyms, or Janus words, that encapsulates its own opposite.
To split or sever in two. To stick fast or firmly adhere to. Flip a coin and take your choice, Dr Schrödinger.