With a transaction, you transfer Bitcoin from your Bitcoin wallet to another party. This transaction or payment will be signed off with your private key and forwarded to the node in the Bitcoin network. This is propagated across the whole network until it reaches a miner, which can confirm the transaction. 

A Bitcoin transaction attracts a fee which is paid to the miner. Under normal circumstances fees amount between one and five cents. However during peak times these may increase noticeably to values of 50 cents or even one euro. If you pay too little in fees, you will have to wait longer for confirmation of your transaction. Most wallets select the appropriate fees. Wallets like BitBucks, in which transactions can also be internally calculated, can save you fees and accelerate confirmation of your transactions.

Top-ups and pay-outs are free of charge for merchants who use the BitBucks app. Payments within the wallet are charged a transaction fee of one percent. In comparison, payments by credit card in Germany usually cost merchants between two and four percent (excluding fees for card terminal providers) and are therefore much more expensive.

If you make the transaction yourself - no. Transactions are pseudonymised and processed by a network without distinction. As Bitcoin is a decentralised network, there is no central location with the power to prevent other nodes from carrying out and verifying transactions - as long as these are covered and valid according to the rules of the network. 

A Bitcoin wallet is software you can use to administer your bitcoins. There are many wallets for all common computer systems. You can choose between local and online wallets. A local wallet gives greater independence and privacy, while an online wallet can offer more convenience.