There are 3 more issues involved.

The first is what type of current is output: DC, AC, etc. If this is not shown directly, it might be indicated by a solid line over a dotted line. This must be the same for both power supplies.

Secondly is the polarity of the connector, but this does not apply if the power supply puts out AC current. This is usually indicated by a dot with a line extending one way, partially surrounded by a semi-circle with another line extending in the oppposite direction. At the and of each line there will be a "+" or a "-". This indcation must also be the same between the two power supplies.

Finally is the connector isself. It must be the same format, or at least close in the case of "barrel" connectors, which are the most common for power supplies. The vital stats are the outer diameter (or O.D.) and the inner diameter (I.D.). Not only must the connector "fit", but it must make good electrical contact. Even if the connectors are slightly different it will most likely still work.

The first two items are critical -- if they are not the same you could damage the computer and/or the power supply. However, as long as the first two are OK, the third will not damage anything even if the connectors don't actually connect. It just won't work.