Talk:Commands/List of Commands/@comment-37108165-20190323000526/@comment-7253572-20190327142857

Invisible mobs: splash potion of invisibility, or /effect @e[type=!player,c=1] invisibility 2000000 1 true gives closest non-player (mob) 2 million seconds of invisibility.

Invisible blocks: /give @s barrier 64 Education Edition must be enabled for barrier blocks, and Invisible Bedrock can only be obtained with mods (search "mc mod unobtainable items") or inventory editors.