Block and chain, because word suggests, a sequence made of blocks! So we know very well what are these blocks. Blocks are a kind of database! People who develop computers know databases well! And for people who do not know, if we say in simple language, then this database is https://josueilml16273.madmouseblog.com/11037275/what-is-blockсhain-technology-and-how-does-it-work