该命令显示系统中的空闲内存、已使用的物理内存和交换内存的总量，以及内核所使用的缓冲区。

The command displays the total amount of free, used physical, and swap memory in the system, as well as the buffers used by the kernel.

youdao

现在应用程序使用了143 MB的物理内存，其余的内存均被缓冲区占用；另外，系统现在使用了18 MB的交换空间。

Now applications have used 143mb of physical memory, with the rest of being used for buffers; in addition, the system now needs to make use of 18mb of swap.

youdao

此处对缓冲区大小所设置的限制是为了优化消息交换的性能。

The limitations on buffer size set here are for optimizing the performance of message exchanges.

youdao