Radio Shack is useless for parts. The biggest parts places are
www.mouser.com,
www.digikey.com,
www.jameco.com and
www.newark.com
Prefixes usually refer to the manufacturer. Thus an LM555, uA555,= and a NE555 are the same part. Then someone comes along like
www.nteinc.com who makes replacement semiconductors with their own numbering system and calls it an NTE9555. CD4053 and an MC4053 are the same too and sometimes it's just referred to as a 4053 just like the 555 is. Suffixes could mean accuracy or temperature range etc. There may be date codes on an IC and country of origin codes.
Now there are "markings" and I havn't figured them out at all. There isn't enough room on a component to put all the numbers.
A 100 ohm resistor could be 100 ohm, 101. On a schematic it could be 100, 100R, 100., 100 Ω
Yea. it's a mess. I've been doing this since I was maybe 10 years old when there were tubes. Surface mount is driving me nuts.