How is the word laud and welcome different

Definition of laud: praise (a person or their achievements) highly, especially in a public context.

welcome:an instance or manner of greeting someone.

I dont see how these could be similar but they are similar in greeting someone. Yet one is greeting someones achievements and the other greeting someone to a place ( home, food area etc. )

the following key ideas correctly express the key sentence.

restate key idea: most people can learn to swim in ten short lessons.

restate key idea: the majority of water-accident victims require mouth-to-mouth breathing.

restate key idea: an empty, tightly closed gallon jug will support a tired swimmer.  

restate key idea: first aid is to prevent accidents as well as assist in rescue.

explanation: the key idea needs to have the same topic as the key sentence (drowning and safety).