Could someone please tell me what these 2 meanings mean

Spamming is the case where a person uses 1 unit in a squad to attack or take someone or something from someone, this is used by a lot of players in the game and is always regarded as a good tactic if you wish to expand at a good rate.

Sniping is the case in which a person launches on something they wish to take and someone else attacks it either with 1 tick less attack time or with more units purposely just to stop you from taking it. This is considered rude and an insult against many players.