PP: it is the meaning for Private Placement. A Private Placement is usually done by investment funds when a Company needs cash to operate, to expand.
It is positive as it means investment funds are interested in a company and believe in the future. It also creates a new bottom, The negative point is a PP is usually done under the current SP, generally lowers the SP and brings dilution.
Dilution: this terms means the float ( the number of shares available on the open market) will be diluted, and resulting to more shares on the open market.
Don’t forget a small float is better than a big float if you want to see great moves.