Strings
Move does not have a native type for strings, but it has a useful wrapper.
module examples::strings {
    use sui::object::{Self, UID};
    use sui::tx_context::TxContext;
    // Use this dependency to get a type wrapper for UTF-8 strings
    use std::string::{Self, String};
    /// A dummy Object that holds a String type
    struct Name has key, store {
        id: UID,
        /// Here it is - the String type
        name: String
    }
    /// Create a name Object by passing raw bytes
    public fun issue_name_nft(
        name_bytes: vector<u8>, ctx: &mut TxContext
    ): Name {
        Name {
            id: object::new(ctx),
            name: string::utf8(name_bytes)
        }
    }
}
String literals
Define string literals in Move as byte strings. To do so, prepend b to your string.
const IMAGE_URL: vector<u8> = b"https://api.capy.art/capys/";
let keys = vector[
            utf8(b"name"),
            utf8(b"link"),
            utf8(b"image_url"),
            utf8(b"description"),
            utf8(b"project_url"),
            utf8(b"creator"),
        ];