In this illustration about CRISPR function, what do these objects mean (image provided)?
The arrow direction denote transcription direction and its location denotes the transcription start site. The circle is probably the transcription terminator (I cannot access this article at the moment, but this is what it should mean).

The purple boxes refer to the protospacers which are derived from foreign DNA. These elements help in recognizing and cleaving foreign DNA. These are transcribed as RNA which in turn guide the Cas complex to the target DNA. In a way, these protospacers provide some kind of immunological memory to the bacteria. See the below figure (From Nuñez et al. 2015 ):