Payments in Bitcoin
Payments are an important aspect of Bitcoin. Every transaction is a payment of some sort. Transactions are the only means through which information can be written onto the ledger. The process of block discovery is agreed upon through the acceptance of a coinbase transaction as a valid payment. A block is simply the process of having a collection of payments set down, collated and agreed upon as valid.
There are many different ways to request and make payments.
BIP21
BIP21 has been one of the predominant means of making mobile payments in Bitcoin throughout it's history. It is an extension of [https://tools.ietf.org/html/rfc3986 the RFC standard for URIs (Universal Resource Identifiers). The BIP21 spec is here
BIP0070
BIP0070 was a payment protocol for reaching out to receivers using a