I have go through multiple websites to find more info on the SPI protocol communication, and found a contradiction between two of these explanations:

1. The bit transmission starts with master sending LSB first to slave and continue to exchange 1 bit at a time. The LSB on master will become the MSB of slave, and LSB of slave becomes MSB of master. The LSB of master will continue to shift until it becomes the LSB of slave. The image below will show how the order will conduct:
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   Before bit transmission

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   After 1 bit transmission

2. The first byte send to the slave are in MSB first and the slave will response it back in LSB first format.
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I am confused on how this SPI protocol works or really the LSB or MSB is not important? It is just to provide some sort of agreement between master and slave so they understand what bit is transferred first. If I were to do the SPI comm would I need to consider how the bit transmission is being sent(MSB/LSB) or will it be transparent to the user?