Well, While both might seem nonsensical at a glance, cyphers and conlangs are very different. A cypher is used to encode messages in an existing language. Some more commonly known cyphers are pigpen and Morse. Conlangs, or 'constructed languages' are completely made up languages that have their own grammar and vocabulary. Some more well known languages are Tsevhu (a.k.a. Koilang) and Toki Pona. Now, some cyphers will pose themselves as languages, but are still cyphers (For example, Gallifreyan and Minecraft enchanting table). Generally, the rule of thumb is: If you can convert normal English text into said 'language' by only changing letters for symbols, it's a cypher. Short hands (Such as Gregg's) are also considered cyphers.