What's the difference between "room"and"space"?eg:There is more——inside the new train

oom:有两层含义,一为“房间”,是可数名词；二表示人或物体所占的“空间或场所”、处事的“余地”等意思,是不可数名词,可用little,much,no,plenty等词修饰.可构成make room for给.让出地方；take up room占地方；leave room for留出空间给.等短语.
There is room in improvement in your work.
你在工作上还有上升空间.
space:意为“空间”,是不可数名词,表示万物存在之处,太空；作“空隙、空白”解时,是可数名词.
There isn’t space in the classroom for thirty desks．