There are six types of standard Bitcoin transactions at present. Developers behind Bitcoin have been constantly developing more types of deals to provide more functionality – the current list may change in the future. There are five typical transactions accepted by standard customers – although some miners will accept a non-standard deal at a reasonable price.
The most common type of transaction is TX_PUBKEY, which is also known as payment for public key transactions – with over 99% of total transaction volume up to 2014.
These percentages are expected to change when the Bitcoin community introduces wallets and other ancillary services using for different types of transactions.
The problem with the more complicated transactions is that they occupy more space in the blockchain thus leading to problems with volume. This problem has emerged in 2015 as developers and economists try to find a balance between confirming direct trades and miners’ requiring of limit the providing space.